2002 Windsor Electrical Issue & NEW Three (3) Phase CG Pedestal Discussion - MERGED

[Chargerman]

Wow! Those are amazing

4 hours ago, joecfd1 said:

My building is 240/120 3 phase. Two of the legs to neutral will give you 120v while the other “high leg” or “stinger leg” to neutral will give you 240 volts…

 

Got it. Good luck with the repair  

[Tom Cherry]

5 hours ago, joecfd1 said:

My building is 240/120 3 phase. Two of the legs to neutral will give you 120v while the other “high leg” or “stinger leg” to neutral will give you 240 volts…

 

I’m about as confused as many seem to be.  A STANDARD RV 50 AMP male plug as a Hot 1 & Hot 2.  These are the vertical side lugs.  If you measure from Hot 1 to Hot 2, then you get 120 X 2 or 240 VC.  The MH male Plug does NOT have an INTERNAL bonded Ground to Neutral that goes back to the main panel.  The Main panel in the MH is different from a residential.  In the residential panel, the Ground and Neutral are BONDED….so you would measure 120 from Hot 1 or Hot 2 to either Ground or Nuetral.

The correct NEC or Code RV pedestal receptacle MUST have a Bonded Ground to Neutral.  So, if you pulled the cover or probed the ternminals, HOT 1 to Hot 2 is 240 VAC.  Hot 1 or Hot 2 to EITHER Ground or Neutral is 120 VAC.

The term “one or 1 phase” means that it is a conventional commercial or industrial SINGLE PHASE service or Configuration.  This is the SAME as one has at Home.  The only reason to call it ONE or 1 Phase to to classify it as NOT BEING A 3 PHASE 220 or 440 (yes…there were a lot of OLD 220 3 phase plants.

OK…you have, at least to me, a very “unique” electical configuration…..here is the definition….

a 120/240 volt 3-phase system, the high leg voltage, also known as the wild leg or stinger leg, is typically 208 volts. This voltage is the result of a phase shift between the different legs of the system. It's important to be cautious when working with such systems to avoid any safety hazards

These systems were NOT designed for real (stoves, dryers, HVAC, etc) devices as the Hot to Hot is more than 10% below the intended 240 VAC potential…so they will be operating below the intended or standard voltages.  How rare?  Don’t know? But if have motors that have 240 windings, they ain’t gonna last long.

NOW…will that work in your Motor Home.  Probably, but it MUST be wired as follows….

Phase A and Phase C will be HOT 1 and HOT 2.  Do NOT USE Phase B.  Neutral will be Neutral.  The GROUND in the panel where the circuit breakers are MUST have the Neutral and Ground Bonded.

NOW from a CODE STANDPOINT….a 3 Phase Panel can NOT be used for the RV Plug.  You have to run a “MODIFIED” 3nphase (A & B….NOT C plus the Neutral and Ground) to a conventional single Phase 240 VAC SubPanel. That will have a single 50 Amp Line1/Line2 DUAL Pole or a single “bonded” 2 leg CB.  Thus, if ONE leg trips the breaker, you MUST also trip the OTHER side.

NOW…I can’t speculate on what legs and such you have from the text.  BUT, from a code standpoint, this is the general requirements.  Rick (Waterskier) can probably provide the nitpicky details, but from a practical standpoint, this is the way it would be done.  In addition, the receptacle must be labeled as 240 VAC 3 phase….208 VAC Hot 1 - Hot 2.  
 

YES….there are NO 240 vac devices in the Motor Home….so, IF and I say IF, the above configuration was used, then a standard MH shore line should WORK.

BUT, until a certified electrician reviews this and then traces the circuit, I would NOT plug my Camelot into it…  I have seen “non standard” 50 A pedestals in businesses that had two single sided breakers and you never knew what might happen.  Mine would NOT work and blew one leg….but a 2008 Navigator with the standard SurgeGuard ATS worked.  My rig has the Progressive HW50C and it tripped the breaker and gave an error code.  So, I used Genny….  Electricity be strange….Ben Franklin ran the same “uninformed” key experiment and got a short jolt almost like a static electricity charge…but a European experimenter was KILLED or electrocuted doing the same drill.

That’s my take….get a REAL, CODE APPROVED receptacle….or risk the devices…

 

[joecfd1]

It looks as if it's the inverter. I'm not getting A/C out of the inverter to the inverter sub panel on either circuit. Definitely have A/C in to both though.The transfer switch seems okay.

Edited January 15 by joecfd1

[Dr4Film]

Sounds like the errant 240 VAC cooked your Inverter.

[jacwjames]

In a previous post I put in contact information for a repair facility that I called when I though my inverter was bad.  They were very helpful

I was told that parts for my RV2012 Trace inverter were pretty much obsolete. 

[Benjamin]

The plug is wired incorrectly with the high leg of the three phase service.  You should not have 240V to ground.  You should only get 240V between the two hot legs, each 120V to ground.  If you know that, and that's been corrected, please confirm the status of whether anything else has changed.

Earlier you said the inverter was working, is it not working now? 

You said the transfer switch seems OK? Is there AC power going OUT from the transfer switch to the breaker panel?  Typically, a 2kw inverter will only feed a few circuits and be downstream of the breaker panel when hooked to shore power, it will not feed all of the breaker panel or affect the transfer switch (between generator and shore power).

Edited January 15 by Benjamin

[joecfd1]

1 hour ago, Benjamin said:

The plug is wired incorrectly with the high leg of the three phase service.  You should not have 240V to ground.  You should only get 240V between the two hot legs, each 120V to ground.  If you know that, and that's been corrected, please confirm the status of whether anything else has changed.

Earlier you said the inverter was working, is it not working now? 

You said the transfer switch seems OK? Is there AC power going OUT from the transfer switch to the breaker panel?  Typically, a 2kw inverter will only feed a few circuits and be downstream of the breaker panel when hooked to shore power, it will not feed all of the breaker panel or affect the transfer switch (between generator and shore power).

Yes, we were using 2 of 3 poles on a 3 phase breaker… problem is that I picked up the high leg mistakenly. The inverter works off of the batteries but won’t pass a/c thru to feed the sub panel while running on either the generator or shore power. Also, the battery charging doesn’t work either. I’ve bypassed the inverter for a trip that I’m loading up for currently. It’s dry camping in the desert so I’ll be using the generator and a stand a lone battery charger until return. Thanks for all it the input.

[Doug Hoegh]

On 1/13/2024 at 5:12 PM, Tom Cherry said:

I’m about as confused as many seem to be.  A STANDARD RV 50 AMP male plug as a Hot 1 & Hot 2.  These are the vertical side lugs.  If you measure from Hot 1 to Hot 2, then you get 120 X 2 or 240 VC.  The MH male Plug does NOT have an INTERNAL bonded Ground to Neutral that goes back to the main panel.  The Main panel in the MH is different from a residential.  In the residential panel, the Ground and Neutral are BONDED….so you would measure 120 from Hot 1 or Hot 2 to either Ground or Nuetral.

The correct NEC or Code RV pedestal receptacle MUST have a Bonded Ground to Neutral.  So, if you pulled the cover or probed the ternminals, HOT 1 to Hot 2 is 240 VAC.  Hot 1 or Hot 2 to EITHER Ground or Neutral is 120 VAC.

The term “one or 1 phase” means that it is a conventional commercial or industrial SINGLE PHASE service or Configuration.  This is the SAME as one has at Home.  The only reason to call it ONE or 1 Phase to to classify it as NOT BEING A 3 PHASE 220 or 440 (yes…there were a lot of OLD 220 3 phase plants.

OK…you have, at least to me, a very “unique” electical configuration…..here is the definition….

a 120/240 volt 3-phase system, the high leg voltage, also known as the wild leg or stinger leg, is typically 208 volts. This voltage is the result of a phase shift between the different legs of the system. It's important to be cautious when working with such systems to avoid any safety hazards

These systems were NOT designed for real (stoves, dryers, HVAC, etc) devices as the Hot to Hot is more than 10% below the intended 240 VAC potential…so they will be operating below the intended or standard voltages.  How rare?  Don’t know? But if have motors that have 240 windings, they ain’t gonna last long.

NOW…will that work in your Motor Home.  Probably, but it MUST be wired as follows….

Phase A and Phase C will be HOT 1 and HOT 2.  Do NOT USE Phase B.  Neutral will be Neutral.  The GROUND in the panel where the circuit breakers are MUST have the Neutral and Ground Bonded.

NOW from a CODE STANDPOINT….a 3 Phase Panel can NOT be used for the RV Plug.  You have to run a “MODIFIED” 3nphase (A & B….NOT C plus the Neutral and Ground) to a conventional single Phase 240 VAC SubPanel. That will have a single 50 Amp Line1/Line2 DUAL Pole or a single “bonded” 2 leg CB.  Thus, if ONE leg trips the breaker, you MUST also trip the OTHER side.

NOW…I can’t speculate on what legs and such you have from the text.  BUT, from a code standpoint, this is the general requirements.  Rick (Waterskier) can probably provide the nitpicky details, but from a practical standpoint, this is the way it would be done.  In addition, the receptacle must be labeled as 240 VAC 3 phase….208 VAC Hot 1 - Hot 2.  
 

YES….there are NO 240 vac devices in the Motor Home….so, IF and I say IF, the above configuration was used, then a standard MH shore line should WORK.

BUT, until a certified electrician reviews this and then traces the circuit, I would NOT plug my Camelot into it…  I have seen “non standard” 50 A pedestals in businesses that had two single sided breakers and you never knew what might happen.  Mine would NOT work and blew one leg….but a 2008 Navigator with the standard SurgeGuard ATS worked.  My rig has the Progressive HW50C and it tripped the breaker and gave an error code.  So, I used Genny….  Electricity be strange….Ben Franklin ran the same “uninformed” key experiment and got a short jolt almost like a static electricity charge…but a European experimenter was KILLED or electrocuted doing the same drill.

That’s my take….get a REAL, CODE APPROVED receptacle….or risk the devices…

 

Tom are you confident it’s against code to use a three phase system for RV installations If wired correctly. I have a three phase 120/208 system without the high leg at my personal storage garage condo and it passed Colorado and the NEC when installed without any problem.

[Tom Cherry]

42 minutes ago, Doug Hoegh said:

Tom are you confident it’s against code to use a three phase system for RV installations If wired correctly. I have a three phase 120/208 system without the high leg at my personal storage garage condo and it passed Colorado and the NEC when installed without any problem.

I AM NEVER confident about any inspector or code.  All I said, and I will modify it...  I WONDER how the NEC would want the pedestal wired.  I AM confident that I KNOW how I would want it done...

Seriously...  Rick is our CODE Specialist....BUT, in all fairness to him, without knowing the "DOMINANT AUTHORITY" as the Local Building Inspector is GOD, it, to me would be a guess.  

The thing I would look at and do a measurement on the RECEPTACLE or PEDESTAL... 

What is the HOT to HOT voltage. If you have the THREE PHASE SYSTEM...  You should have 208 (or thereabouts) between the two rectangular or parallel legs.  HINT...I don't have a meter with long probes...so I often just "back out" a little....and put my probes on the lugs of the 4 Prong 50 Amp receptacle.

What is the HOT 1 and HOT 2 voltage to BOTH GROUND and NEUTRAL.  Should be exactly the same....within a tenth or so of a volt.

Using the Continuity or OHMS scale, the Neutral to Ground should be a COMPLETED CIRCUIT....or if one likes, try the AC Volts....should be almost zero...transient voltages may appear depending on the wiring and the meter....but those TWO terminals have to be BONDED upstream of the service.....or at the FIRST PANEL. 

NOW....it gets TRICKY.  MAYBE THERE IS A Crazy Breaker....but I still stick by my logic.  You run service from the MAIN PANEL  (3 Ph 120/208) to a DEDICATED subpanel with a DUAL 50 A breakers....in that, when ONE LEG trips....BOTH TRIP.  

Now if there are TWO 50 Amp Breakers in the MAIN 120/208 and the are NOT Tied (as in a "nail" or rod or small bolt) connects them...so that when ONE BREAKS...it carries the other....I WOULD BE CAUTIOUS

I have seen some "less than code" installations, one of which resulted in a fire...  A buddy is a Captain in the local Large Municipal FD and also the Asst Chief of the semi Paid/Volunteer local rural fire department. I had to replace a dangerous FPE 120/240 Panel.  We had an old time (was LEGAL THEN) wiring issue where there was a COMMON Neutral for two circuits....and NOT a dedicated Neutral for EVERY Breaker. The ONLY way to resolve was to put in DUAL 120 Breakers.  Then when ONE leg tripped, it took the OTHER circuit with it.  Sort of STRANGE...but that is the CODE approved solution to prevent feedback up a Neutral.

I KNOW there was feedback....and got over 100 VAC from a neutral that had the Dedicated Breaker TURNED OFF.  Scared the whatever out of me..  SO, I got a licensed high quality Electrical Contractor to put in a new panel and we populated every receptacle or outlet circuit with the DUAL breakers....so that there was NOT the risk of a feedback voltage. IT WORKED...  My friend, who is a church member and I also tested the system and BOTH breakers trip when one is shorted.

My POINT...  I THINK that code would require a dedicated "240" 50Amp Breaker in the Sub Panel or at the Pedestal.  Do the Voltage and Continuity Measurements.  IF OK then fine.  IF NOT?

It would be good to take a picture of where the 50 Amp Breaker is located....on the Pedestal or in a sub panel...

That's my take....

[Doug Hoegh]

3 hours ago, Tom Cherry said:

I AM NEVER confident about any inspector or code.  All I said, and I will modify it...  I WONDER how the NEC would want the pedestal wired.  I AM confident that I KNOW how I would want it done...

Seriously...  Rick is our CODE Specialist....BUT, in all fairness to him, without knowing the "DOMINANT AUTHORITY" as the Local Building Inspector is GOD, it, to me would be a guess.  

The thing I would look at and do a measurement on the RECEPTACLE or PEDESTAL... 

What is the HOT to HOT voltage. If you have the THREE PHASE SYSTEM...  You should have 208 (or thereabouts) between the two rectangular or parallel legs.  HINT...I don't have a meter with long probes...so I often just "back out" a little....and put my probes on the lugs of the 4 Prong 50 Amp receptacle.

What is the HOT 1 and HOT 2 voltage to BOTH GROUND and NEUTRAL.  Should be exactly the same....within a tenth or so of a volt.

Using the Continuity or OHMS scale, the Neutral to Ground should be a COMPLETED CIRCUIT....or if one likes, try the AC Volts....should be almost zero...transient voltages may appear depending on the wiring and the meter....but those TWO terminals have to be BONDED upstream of the service.....or at the FIRST PANEL. 

NOW....it gets TRICKY.  MAYBE THERE IS A Crazy Breaker....but I still stick by my logic.  You run service from the MAIN PANEL  (3 Ph 120/208) to a DEDICATED subpanel with a DUAL 50 A breakers....in that, when ONE LEG trips....BOTH TRIP.  

Now if there are TWO 50 Amp Breakers in the MAIN 120/208 and the are NOT Tied (as in a "nail" or rod or small bolt) connects them...so that when ONE BREAKS...it carries the other....I WOULD BE CAUTIOUS

I have seen some "less than code" installations, one of which resulted in a fire...  A buddy is a Captain in the local Large Municipal FD and also the Asst Chief of the semi Paid/Volunteer local rural fire department. I had to replace a dangerous FPE 120/240 Panel.  We had an old time (was LEGAL THEN) wiring issue where there was a COMMON Neutral for two circuits....and NOT a dedicated Neutral for EVERY Breaker. The ONLY way to resolve was to put in DUAL 120 Breakers.  Then when ONE leg tripped, it took the OTHER circuit with it.  Sort of STRANGE...but that is the CODE approved solution to prevent feedback up a Neutral.

I KNOW there was feedback....and got over 100 VAC from a neutral that had the Dedicated Breaker TURNED OFF.  Scared the whatever out of me..  SO, I got a licensed high quality Electrical Contractor to put in a new panel and we populated every receptacle or outlet circuit with the DUAL breakers....so that there was NOT the risk of a feedback voltage. IT WORKED...  My friend, who is a church member and I also tested the system and BOTH breakers trip when one is shorted.

My POINT...  I THINK that code would require a dedicated "240" 50Amp Breaker in the Sub Panel or at the Pedestal.  Do the Voltage and Continuity Measurements.  IF OK then fine.  IF NOT?

It would be good to take a picture of where the 50 Amp Breaker is located....on the Pedestal or in a sub panel...

That's my take....

 

Just now, Doug Hoegh said:

 

I have a two pole 50 amp breaker no different than with a single split phase system.  And I might add I’m seeing new campgrounds with three phase systems being used for pedestal installations. Mike Sokol, the guy behind RV Electricity and other websites has discussed it at length.  Seems to be a more efficient way to handle the install as long as it’s correctly balanced.

[waterskier_1]

I would have to research the NEC and any local building code modifications to that.  I'm quite confused with the term single phase 240 VAC.  I have always considered the 50 Amp 240 that is supplied in the pedestal to be "split phase".  If it were "single phase" you would not have 240 between the legs.  You would have 120 leg to neutral though.  This is similar to what the Onan generators in the 5KW to 8KW range supply.  But the 10KW and 12.5KW generators have true "split phase" output yielding 240 leg to leg.  This may be a terminology issue, but single phase does not yield 240 leg to let, split phase does have 240 leg to let. 

As far as the NEC not allowing this, the most common case is 120 Leg to neutral, and 208 leg to leg.  Many "240 VAC" devices are rated "208VAC to 240VAC" which clears up the difference.  I agree that a 240 VAC only device (load) would not operate correctly on 208VAC.  But only some newer, high end (i.e., Prevost) coaches actually use 240VAC for dryers.  I'm not aware of any using 240VAC A/C units, but they could be. 

  -Rick N.

Quartzsite, AZ 

[Benjamin]

The accident was connecting the high leg to the 50A RV outlet.  That connected one leg of the RV to 240V to ground, instead of the normal 240V leg to leg, 120V to ground.  Whatever you call it, single phase vs split phase, and whether it is code to connect off a three phase service are other questions, not really relevant, as the RV would have functioned 100% correctly if the high leg had not been mistakenly connected.

[Doug Hoegh]

6 hours ago, waterskier_1 said:

I would have to research the NEC and any local building code modifications to that.  I'm quite confused with the term single phase 240 VAC.  I have always considered the 50 Amp 240 that is supplied in the pedestal to be "split phase".  If it were "single phase" you would not have 240 between the legs.  You would have 120 leg to neutral though.  This is similar to what the Onan generators in the 5KW to 8KW range supply.  But the 10KW and 12.5KW generators have true "split phase" output yielding 240 leg to leg.  This may be a terminology issue, but single phase does not yield 240 leg to let, split phase does have 240 leg to let. 

As far as the NEC not allowing this, the most common case is 120 Leg to neutral, and 208 leg to leg.  Many "240 VAC" devices are rated "208VAC to 240VAC" which clears up the difference.  I agree that a 240 VAC only device (load) would not operate correctly on 208VAC.  But only some newer, high end (i.e., Prevost) coaches actually use 240VAC for dryers.  I'm not aware of any using 240VAC A/C units, but they could be. 

  -Rick N.

Quartzsite, AZ 

Split phase is a type of single phase power.  That’s all.

[Tom Cherry]

11 hours ago, Doug Hoegh said:

Split phase is a type of single phase power.  That’s all.

As I see it…..some “unkowns”….at least to me.

First….I do NOT know the “tolerance” for the Monaco installed Intellitec EMS or load shedding “L1 - L2” measurement.  Maybe 208 will work.  They are designed to verify a “real” 50 A conventional service.  Will 208 instead of 240 work?  That is NOT a rhetorical question….just a pure and simple question.  

Next up….ATS with power monitoring systems or surge suppressors, hard wired or plug in.  Do they “check” for 240 VAC and will they work with 208.  I believe that the popular Progressive HW50C will throw an error code at 105.  So, if the theroretical value for that is 120, then if any measure L1 to L2, then finding a 208 reading, theroetical, which in a low voltage condition could easily drop to the 190’s….WHAT WILL HAPPEN?

Next up, higher end MH. I THOUGHT….could be wrong….so take with a grain of salt, that some of the upper ends had 240 VAC devices??  Again….my memory.  If so, then how will they react or fare?

Seems to me that if a park went to a 120/208 3 Phase setup, that common sense, courtesy or CODE would require some placards or warnings?

WHOLE lot of questions…

I DID talk to the “field” supervisor of a local large commercial/industrial and occasionally “residential” licensed NC Electrical Contracting company.

This is how he would run a home service or shop with 120/208.  

From main service in building or POINT OF ENTRY.  Neutral and Ground must be BONDED there.  For a SINGLE 50 amp feed…..two options.

First…..both cases….a 3 Pole 50 A breaker in main panel.  Run #6 or possibly #4, length dependent, to point of service.  Would NOT run the B phase….only A & C.

Option 1.  Subpanel there.  Conventional 120/240.  LIne 1 is A and Line 2 is C….can be reversed….  Install a dual pole 50A Breaker.  Run receptacle from it.  Placard or label the receptacle as “NOT 120/240 50 A.  120/208 Phase A & C”.  Needed, per HIS THINKING, maybe NOT code, to prevent someone using on a 240 conventional device.

Option 2.  Run directly to the Receptacle.  CODES MAY require a “pedestal” box with a dual pole 50 A breaker for “Line of Sight” disconnect.  Some may NOT put a Breaker there….but he would.  Then wire as above and placard. NOTE….then if one leg has an issue, the 3 pole breaker at the main panel should trip all THREE legs.

Running without a line of sight disconnect requires an approved OSHA Lock Out Tag OUT shut down of main panel or the 50 A 3 pole breaker…..

NOW REMEMBER, now, or at least in my home, built 1990, the Dryer and Stove and Well do NOT require a breaker at point of service.  Outside HVAC and inside Air Handler do…  in fact, if you swap a Heat Pump with strips, you remove the dual breaker at the air handler (it was a 40 A) and install a single 15 A for the fan and furnace air handler and and properly terminate Line 2 leg and put a “blank” over the opening next to the single 15 A 120 breaker.  CODE and County inspector went to main panel….no need to replace breaker there….but line of site subpanel must be reconfigured. APPROVED….

AGAIN…..that is how he would do it and it would pass local inspection as well as NC code….

 

 

[Doug Hoegh]

5 hours ago, Tom Cherry said:

As I see it…..some “unkowns”….at least to me.

First….I do NOT know the “tolerance” for the Monaco installed Intellitec EMS or load shedding “L1 - L2” measurement.  Maybe 208 will work.  They are designed to verify a “real” 50 A conventional service.  Will 208 instead of 240 work?  That is NOT a rhetorical question….just a pure and simple question.  

Next up….ATS with power monitoring systems or surge suppressors, hard wired or plug in.  Do they “check” for 240 VAC and will they work with 208.  I believe that the popular Progressive HW50C will throw an error code at 105.  So, if the theroretical value for that is 120, then if any measure L1 to L2, then finding a 208 reading, theroetical, which in a low voltage condition could easily drop to the 190’s….WHAT WILL HAPPEN?

Next up, higher end MH. I THOUGHT….could be wrong….so take with a grain of salt, that some of the upper ends had 240 VAC devices??  Again….my memory.  If so, then how will they react or fare?

Seems to me that if a park went to a 120/208 3 Phase setup, that common sense, courtesy or CODE would require some placards or warnings?

WHOLE lot of questions…

I DID talk to the “field” supervisor of a local large commercial/industrial and occasionally “residential” licensed NC Electrical Contracting company.

This is how he would run a home service or shop with 120/208.  

From main service in building or POINT OF ENTRY.  Neutral and Ground must be BONDED there.  For a SINGLE 50 amp feed…..two options.

First…..both cases….a 3 Pole 50 A breaker in main panel.  Run #6 or possibly #4, length dependent, to point of service.  Would NOT run the B phase….only A & C.

Option 1.  Subpanel there.  Conventional 120/240.  LIne 1 is A and Line 2 is C….can be reversed….  Install a dual pole 50A Breaker.  Run receptacle from it.  Placard or label the receptacle as “NOT 120/240 50 A.  120/208 Phase A & C”.  Needed, per HIS THINKING, maybe NOT code, to prevent someone using on a 240 conventional device.

Option 2.  Run directly to the Receptacle.  CODES MAY require a “pedestal” box with a dual pole 50 A breaker for “Line of Sight” disconnect.  Some may NOT put a Breaker there….but he would.  Then wire as above and placard. NOTE….then if one leg has an issue, the 3 pole breaker at the main panel should trip all THREE legs.

Running without a line of sight disconnect requires an approved OSHA Lock Out Tag OUT shut down of main panel or the 50 A 3 pole breaker…..

NOW REMEMBER, now, or at least in my home, built 1990, the Dryer and Stove and Well do NOT require a breaker at point of service.  Outside HVAC and inside Air Handler do…  in fact, if you swap a Heat Pump with strips, you remove the dual breaker at the air handler (it was a 40 A) and install a single 15 A for the fan and furnace air handler and and properly terminate Line 2 leg and put a “blank” over the opening next to the single 15 A 120 breaker.  CODE and County inspector went to main panel….no need to replace breaker there….but line of site subpanel must be reconfigured. APPROVED….

AGAIN…..that is how he would do it and it would pass local inspection as well as NC code….

 

 

I have not had any issues with either my Intellitec EMS load shedding system or my Progressive Industries EMS (hard wired) when connected to my garage’s 208/120VAC 3 phase system.

[Doug Hoegh]

MODERATOR EDIT

This new topic was merged, mistakenly, into the WRONG existing one. Housekeeping is now complete and it is in the one that had morphed into 
"NEW THREE PHASE CG Pedestal Wiring". Sorry for the confusion....Surge Protection, Open Neutrals, AC Electrical, etc. issues have recently dominated the topics.

END EDIT

Recently we had a discussion about three phase power and our coaches.  I thought I would share this link to Mike Sokol's Substack discussing the new code approved use of three phase power for campground pedestal wiring.  Hope you enjoy.  https://open.substack.com/pub/rvelectricity/p/3-phase-campground-power-service?r=1upktj&utm_campaign=post&utm_medium=email

[Scotty Hutto]

Interesting stuff!  And a good warning to check voltages before hooking up - or AT LEAST make sure and use your surge protector!

A surge protector will catch the 208v as “high voltage” and prevent damage to the motorhome.  

I may be a dinosaur, but I have a device that I use to test every new pedestal before I hook up. Has saved me a time or two… (pedestal tester made by our member Richard Smith @Dr4Film)

[96 EVO]

22 hours ago, Scotty Hutto said:

Interesting stuff!  And a good warning to check voltages before hooking up - or AT LEAST make sure and use your surge protector!

A surge protector will catch the 208v as “high voltage” and prevent damage to the motorhome.  

I may be a dinosaur, but I have a device that I use to test every new pedestal before I hook up. Has saved me a time or two… (pedestal tester made by our member Richard Smith @Dr4Film)

Unfortunately Scotty, you 'usually' don't learn much until you start putting a load on the power pedestal!

Will catch mis-wiring, and very low / high voltage.

Edited January 26 by 96 EVO

[b_faster]

Doug, Thanks for sharing.  I haven't seen the high leg delta system in quite some time.  I left the plant world 30 years ago. OH boy it has been 30 years!!

The article is spot on, it is/was prevalent in office buildings in industrial and commercial facilities where a 3-phase system exists, and small split phase is required.  I understand the utilization whereas 3 phase loads systems are present and there is a need for a Single-phase split load.  I cannot for the life of me understand why a campground would utilize this system if they were starting from ground zero the opportunity to make a large mistake is always present. 

[Benjamin]

I would guess a campground with a three phase service would have every transformer split with a neutral to deliver all 120/240 split phase, as there are no three phase RV's there would be no use for the high leg, but there would be use for more capacity. 

I'm not familiar with high amp single phase services and how they would accomplish that, but nearly all distribution and transmission wiring is three phase until close to the end user.  A campground with dozens of 50A pedestals could use the three phase service to provide single phase power without the high leg being a factor, as it shouldn't be unless the electrician messes up. 

[joecfd1]

Follow up on my electrical issue from above. It turned out when I introduced high voltage to the coach I smoked the inverter. I'd like to give a shout out to our member @Mark B for offering up an Trace inverter/charger that he pulled out of his rig. It worked like a champ. Thanks for all for diagnostic tips and info. This forum is a wealth of knowledge.