Lost LINE 1 POWER. 2009 KNIGHT. Maybe the Inverter? Help Appreciated.

[laurice@email.com]

We have a 2009 Monaco Knight PKQ38 and have lost the #1 leg of power off of the inverter.  Had the whole inverter rebuilt when we purchased the coach in 2020 and have not had any isses since. 

Tonight is the coldest night of the season (of course!) and suddenly we lost one side/leg of the power.  We reset the inverter and everything was fine then 10 minutes later it happened again.  

Any words of wisdom would be warmly received and much appreciated. 

Thanks Laurice

[JDCrow]

You are not hooked to shore power? 

[BradHend]

What’s plugged into it?

[laurice@email.com]

Unit is plugged in to shore power. 

[Tom Cherry]

1 hour ago, laurice@email.com said:

We have a 2009 Monaco Knight PKQ38 and have lost the #1 leg of power off of the inverter.  Had the whole inverter rebuilt when we purchased the coach in 2020 and have not had any isses since. 

 

Tonight is the coldest night of the season (of course!) and suddenly we lost one side/leg of the power.  We reset the inverter and everything was fine then 10 minutes later it happened again.  

Any words of wisdom would be warmly received and much appreciated. 

Thanks Laurice

Based on what has been posted.....These are my assumptions

You have a Magnum Inverter per the Manual.  There are THREE Circuit Breakers....these are Pin Style. One is a 30 Amp INCOMING power.  TWO are 20 Amp Outgoing power.  ONE line goes to the INTERNAL Receptacles, through a GFCI. The OTHER line goes directly to the Microwave. HOWEVER....The wording of your post is confusing....so this needs to be responded to so we can help.

IF you have 115 VAC on the Internal Receptacles and the Microwave, then you MAY (Probably?) meant that you have lost LINE 1 ON THE MAIN PANEL.   Let me explain.... There are TWO lines (1 and 2) on the Main Panel.  The AC  GOES DIRECTLY from CG Pedestal via the Shore cord to the  AUTOMATIC TRANSFER SWITCH (ATS). Your MH came with an IOTA 50-R Automatic Transfer Switch. These ATS are a hazard.  They can catch fire and also cause electrical shorts.

PLEASE refer to Page 163 of your Owner's Manual. This is the PICTURE of the Inverter. NAVISTAR recalled and replaced all of these.  BUT, since, like me, your MH was made by the ORIGINAL Monaco company and NOT Navistar, then the "LIABILITY" for Monaco's issues did NOT cover your MH. It is an ORPHAN.

There are TWO INCOMING LINES.  They come through the shore cord. If you read Section 8 of the manual, it explains it. A 50 A Pedestal has a Dual Pole 50 Amp Breaker. There are FOUR wires inside the Shore Cable. One is Black and one is Red. These are Line 1 and Line 2 HOT. There is a WHITE Neutral. There is also  GREEN Ground. You have LOST Line 1 at the MAIN PANEL. There are many places where that can HAPPEN.

The Pedestal receptacle can be defective... The CG can verify that for you.

Your 50 A shore (Male) Plug is NOT INDESTRUCTABLE. Mine failed. It can be replaced with a Camco 50 A RV plug that Amazon sells. This is NOT a complex job. Anyon with electrical knowledge or a residential Electrician can do this. it is NOT something that requires an RV Tech.

There is a Junction Box that connects the LINE (SHore Cord) to the INTERNAL Cable that goes to the ATS.

The ATS can be bad.  In your case, if you STILL have the ORIGINAL IOTA-50R, it needs to be replace IMMEDIATELY. The most popular one is an ESCO or LYGHT 50BRD. I will attach a "Search Results" on the IOTA.  This search has many topics and discussion of replacing the IOTA. It can NOT be stressed enough that his is a fire and personal safety issue and needs to be replaced immediately.

YOU CAN TRY to run the Generator....but sometimes the IOTA will work on one source (Shore or Genny) and NOT on the other.

NOW, if the ATS has been replaced, the next step is to unplug the SHORE and start the Generator. IF you have BOTH Line 1 and Line 2, then there is a problem with the SHORE system....again....follow the above.

I am editing the TITLE as your comment about what is GONE does NOT impact or come through the INVETER.

Typically, the Inverter on a Monaco is on LINE 2....so if you have INTERNAL power (receptacles and microwave), then the INVERTER is working fine.

Please clarify if you mean that you lost MAIN POWER or LINE 1 on the MAIN PANEL....OR if you mean one of the OUTPUT lines on the INVERTER. Look on page 168.  This is the MAIN PANEL.  The AC comes in here. Notice that Line 2, as I suspected, has the 30 Amp Breaker. 

NOW if you mean that you have NO POWER to the FRONT AC or the WATER Heater (or Fireplace option if you have that), then this is a MAIN POWER ISSUE...and NOT an Inverter issue.

If it IS the inverter, then push in the TWO 20 A (may be 15 A) pin circuit breakers on the inverter. They are visible and look like "plastic pins or switches".  If you reset the INVERTER by holding in the POWER BUTTON for 20 seconds (Soft Reset) and all was well and DID NOT have to reset or push in the Circuit breakers....then that is a totally different problem....

It is important to KNOW which power you have lost....so please post....

Hope this helps....

The Inverter has (MOST LIKELY) three (3) Pin Style Circuit Breakers. If you did a SOFT reset of the Inverter and all was well and then you have lost either the internal receptacles or the Microwave....that is Line 1 and Lin3 2.  Without knowing how Monaco wired it up....then it is difficult to say which Line is which. 

SO....exactly what power do you NOT have.  FWIW, there is an Automatic Transfer Switch inside the Magnum.  It is a relay on the MAIN (Control) board. It works this way. When the Inverter can sense or "measure" voltage on the incoming LINE (from the Main Panel). Once the Inverter "sees or senses" the power and has a "functional or good" battery bank, the Inverter then PASSES the power to the TWO CIRCUITS (Internal Receptacles and Microwave). IF you mean that the receptacles or microwave is DEAD, then that IS an Inverter problem...and the ATS can NOT be repaired....it requires a NEW Control Board....

Please give us MORE INFORMATION.  Thanks....

[vito.a]

By any chance are you trying to run an electric space heater from one of the inverter supplied 120V electrical outlets?

[laurice@email.com]

No auxiliary heating being used….ever. 
 

[laurice@email.com]

11 hours ago, Tom Cherry said:

Based on what has been posted.....These are my assumptions

You have a Magnum Inverter per the Manual.  There are THREE Circuit Breakers....these are Pin Style. One is a 30 Amp INCOMING power.  TWO are 20 Amp Outgoing power.  ONE line goes to the INTERNAL Receptacles, through a GFCI. The OTHER line goes directly to the Microwave. HOWEVER....The wording of your post is confusing....so this needs to be responded to so we can help.

IF you have 115 VAC on the Internal Receptacles and the Microwave, then you MAY (Probably?) meant that you have lost LINE 1 ON THE MAIN PANEL.   Let me explain.... There are TWO lines (1 and 2) on the Main Panel.  The AC  GOES DIRECTLY from CG Pedestal via the Shore cord to the  AUTOMATIC TRANSFER SWITCH (ATS). Your MH came with an IOTA 50-R Automatic Transfer Switch. These ATS are a hazard.  They can catch fire and also cause electrical shorts.

PLEASE refer to Page 163 of your Owner's Manual. This is the PICTURE of the Inverter. NAVISTAR recalled and replaced all of these.  BUT, since, like me, your MH was made by the ORIGINAL Monaco company and NOT Navistar, then the "LIABILITY" for Monaco's issues did NOT cover your MH. It is an ORPHAN.

There are TWO INCOMING LINES.  They come through the shore cord. If you read Section 8 of the manual, it explains it. A 50 A Pedestal has a Dual Pole 50 Amp Breaker. There are FOUR wires inside the Shore Cable. One is Black and one is Red. These are Line 1 and Line 2 HOT. There is a WHITE Neutral. There is also  GREEN Ground. You have LOST Line 1 at the MAIN PANEL. There are many places where that can HAPPEN.

The Pedestal receptacle can be defective... The CG can verify that for you.

Your 50 A shore (Male) Plug is NOT INDESTRUCTABLE. Mine failed. It can be replaced with a Camco 50 A RV plug that Amazon sells. This is NOT a complex job. Anyon with electrical knowledge or a residential Electrician can do this. it is NOT something that requires an RV Tech.

There is a Junction Box that connects the LINE (SHore Cord) to the INTERNAL Cable that goes to the ATS.

The ATS can be bad.  In your case, if you STILL have the ORIGINAL IOTA-50R, it needs to be replace IMMEDIATELY. The most popular one is an ESCO or LYGHT 50BRD. I will attach a "Search Results" on the IOTA.  This search has many topics and discussion of replacing the IOTA. It can NOT be stressed enough that his is a fire and personal safety issue and needs to be replaced immediately.

YOU CAN TRY to run the Generator....but sometimes the IOTA will work on one source (Shore or Genny) and NOT on the other.

NOW, if the ATS has been replaced, the next step is to unplug the SHORE and start the Generator. IF you have BOTH Line 1 and Line 2, then there is a problem with the SHORE system....again....follow the above.

I am editing the TITLE as your comment about what is GONE does NOT impact or come through the INVETER.

Typically, the Inverter on a Monaco is on LINE 2....so if you have INTERNAL power (receptacles and microwave), then the INVERTER is working fine.

Please clarify if you mean that you lost MAIN POWER or LINE 1 on the MAIN PANEL....OR if you mean one of the OUTPUT lines on the INVERTER. Look on page 168.  This is the MAIN PANEL.  The AC comes in here. Notice that Line 2, as I suspected, has the 30 Amp Breaker. 

NOW if you mean that you have NO POWER to the FRONT AC or the WATER Heater (or Fireplace option if you have that), then this is a MAIN POWER ISSUE...and NOT an Inverter issue.

If it IS the inverter, then push in the TWO 20 A (may be 15 A) pin circuit breakers on the inverter. They are visible and look like "plastic pins or switches".  If you reset the INVERTER by holding in the POWER BUTTON for 20 seconds (Soft Reset) and all was well and DID NOT have to reset or push in the Circuit breakers....then that is a totally different problem....

It is important to KNOW which power you have lost....so please post....

Hope this helps....

The Inverter has (MOST LIKELY) three (3) Pin Style Circuit Breakers. If you did a SOFT reset of the Inverter and all was well and then you have lost either the internal receptacles or the Microwave....that is Line 1 and Lin3 2.  Without knowing how Monaco wired it up....then it is difficult to say which Line is which. 

SO....exactly what power do you NOT have.  FWIW, there is an Automatic Transfer Switch inside the Magnum.  It is a relay on the MAIN (Control) board. It works this way. When the Inverter can sense or "measure" voltage on the incoming LINE (from the Main Panel). Once the Inverter "sees or senses" the power and has a "functional or good" battery bank, the Inverter then PASSES the power to the TWO CIRCUITS (Internal Receptacles and Microwave). IF you mean that the receptacles or microwave is DEAD, then that IS an Inverter problem...and the ATS can NOT be repaired....it requires a NEW Control Board....

Please give us MORE INFORMATION.  Thanks....

 

[laurice@email.com]

Thank you very much, Tom.  Most helpful.

We did run the generator with the same result. The same results when we switched to solar.

I have verified that the pedestal is providing power.  The Surge suppression system advises that there is power on both legs, 120 volts on line 1 and 122 volts on line 2.  Line 1 draws 6 amps, line 2 is zero (when the number 1 pin breaker on the inverter is tripped)

The ATS is NOT the original one.  We replaced it with another 3 years ago.  I can't find/remember the name of the manufacturer/model of the replacement, but at the time, it was deemed to be the best-performing ATS for RVs and yachts.  I agree fully with you about how dangerous the original one was.  Ours failed, and when the cover was pulled off, the inside was totally burnt.  You could smell the burnt wires and melted cabinet! ANYONE with the original ATS owes it to themselves to replace the ATS as soon as possible.

At the electrical panel, I have similar voltages (to the exterior measurements at the surge suppression system) on either side of the main breaker when measured individually.  One interesting thing is that I have a combined voltage of approximately 240 volts when measured individually, when I measure the voltage across both sides of the main breaker, I get 207 volts.  I don't understand that, but that's a whole different concern now.

When the pin on the inverter is tripped, the fridge, washer/dryer worked fine.  However, all other outlets and the microwave have no voltage.  

Once I reset the first pin breaker on the ATS everything works perfectly.  But 10 minutes later it tripped again.  I then reset the pin breaker again, took the water heater off 120 and placed it on 12 volts, and all has been fine since.  My thinking is that there is too much load on the one side.  Does that make sense?

One other item that may be a factor is that when we purchased the coach, the inverter had to be sent back to the manufacturer for repair or replacement.  It was repaired and since we have not had an issue.

I hope this provides a better understanding of my situation

Thanks again for your assistance, much appreciated.

Laurice

[MyronTruex]

The water heater should not be on the inverter. However, who knows who or what modifications may have been done. It should be very easy to determine by simply finding the (likely 30 amp breaker), that feeds the inverter. Turning it off will disable the inverter/converter but you should still have power to the water heater assuming you are on 50 amps or the generator is running. 

I will assume you have a Magnum 2012 or the pure sine wave one for argument.

As mentioned, two separate output paths from one input (30 amp) path. Those small breakers on the inverter/charger can fail, or you could have an overload on one of them.

One path goes to the microwave, and the other to some less hungry circuits. 

I'm not sure what a (rebuild) would have entailed other than an inspection and cleaning. 

The one path that is failing could be a bad connection on the actual breaker inside the Magnum as I found on mine. 

IF you are comfortable with 110 volts and a meter, you could probably disconnect the two output hots, then move the wire on the breaker that is popping to the other location. There is a simple tie down board on the inverter and you do not have to take it apart, but you do have to remove input power of course. 

If that breaker now pops, you have some sort of load that is too large, and if the water heater is on that leg by design or accident, that could be an issue. 

I suspect this problem just came up so the likelihood of the water heater being on that circuit is minimal. 

[96 EVO]

Your GFCI outlet (usually in the bathroom) isn't tripping?

[Admirial RVr]

Un plug your micro wave and see if that Pin Breaker on the inverter trips. Could be a bad receptical for the microwave.

I recently had a similar problem and ended up replacing receptical and the pin breaker.

[laurice@email.com]

Thanks will try that.  

3 hours ago, MyronTruex said:

The water heater should not be on the inverter. However, who knows who or what modifications may have been done. It should be very easy to determine by simply finding the (likely 30 amp breaker), that feeds the inverter. Turning it off will disable the inverter/converter but you should still have power to the water heater assuming you are on 50 amps or the generator is running. 

I will assume you have a Magnum 2012 or the pure sine wave one for argument.

As mentioned, two separate output paths from one input (30 amp) path. Those small breakers on the inverter/charger can fail, or you could have an overload on one of them.

One path goes to the microwave, and the other to some less hungry circuits. 

I'm not sure what a (rebuild) would have entailed other than an inspection and cleaning. 

The one path that is failing could be a bad connection on the actual breaker inside the Magnum as I found on mine. 

IF you are comfortable with 110 volts and a meter, you could probably disconnect the two output hots, then move the wire on the breaker that is popping to the other location. There is a simple tie down board on the inverter and you do not have to take it apart, but you do have to remove input power of course. 

If that breaker now pops, you have some sort of load that is too large, and if the water heater is on that leg by design or accident, that could be an issue. 

I suspect this problem just came up so the likelihood of the water heater being on that circuit is minimal. 

Great suggestion.  Will try this out.  Much appreciated

3 hours ago, 96 EVO said:

Your GFCI outlet (usually in the bathroom) isn't tripping?

GFCI has not tripped. Thanks for the suggestion. 

[Tom Cherry]

3 hours ago, laurice@email.com said:

Thank you very much, Tom.  Most helpful.

We did run the generator with the same result. The same results when we switched to solar.

I have verified that the pedestal is providing power.  The Surge suppression system advises that there is power on both legs, 120 volts on line 1 and 122 volts on line 2.  Line 1 draws 6 amps, line 2 is zero (when the number 1 pin breaker on the inverter is tripped)

The ATS is NOT the original one.  We replaced it with another 3 years ago.  I can't find/remember the name of the manufacturer/model of the replacement, but at the time, it was deemed to be the best-performing ATS for RVs and yachts.  I agree fully with you about how dangerous the original one was.  Ours failed, and when the cover was pulled off, the inside was totally burnt.  You could smell the burnt wires and melted cabinet! ANYONE with the original ATS owes it to themselves to replace the ATS as soon as possible.

At the electrical panel, I have similar voltages (to the exterior measurements at the surge suppression system) on either side of the main breaker when measured individually.  One interesting thing is that I have a combined voltage of approximately 240 volts when measured individually, when I measure the voltage across both sides of the main breaker, I get 207 volts.  I don't understand that, but that's a whole different concern now.

When the pin on the inverter is tripped, the fridge, washer/dryer worked fine.  However, all other outlets and the microwave have no voltage.  

Once I reset the first pin breaker on the ATS everything works perfectly.  But 10 minutes later it tripped again.  I then reset the pin breaker again, took the water heater off 120 and placed it on 12 volts, and all has been fine since.  My thinking is that there is too much load on the one side.  Does that make sense?

One other item that may be a factor is that when we purchased the coach, the inverter had to be sent back to the manufacturer for repair or replacement.  It was repaired and since we have not had an issue.

I hope this provides a better understanding of my situation

Thanks again for your assistance, much appreciated.

Laurice

Back to the basics.  Power comes in from shore.  Then from the shore line to the ATS.  Then to the Main Panel.  Your inverter is on the 30 Amp breaker that is, per the label in the manual, on LINE 2.

NOW….there is NO correlation between calling the Line 1 and Line 2 on the main panel and the “Line 1 and Line 2” designations on the inverter.

The inverter is splitting the 30 amp feed into two INVERTER circuits.  Think about them as being INV Line 1 and INV line 2.

There is a 30 Amp Pin CB on the Magnum.  That is the INCOMING power.  It is fed from the upstream Main Panel 30 A breaker on House Line 2.

There are TWO 20 Amp pin style Circuit Breakers on the OUTPUT side. They can be called or labeled anyway.  Lets call them INV Line 1….and INV Line 2.  One is a dedicated circuit going to the Microwave.  The other is the HOUSE Interior Receptacles. That line goes directly to a GFCI receptacle, usually in the center hall on the front of the vanity cabinet.  THEN the Load or protected side goes to the outlets a d the refrigerator ICEMAKER outlet,

What I BELIEVE you are experiencing is a 20 Amp Pin Circuit breaker tripping on the Magnum Inverter.

IF that circuit breaker and the same one trips and you do NOT have something like a portable space heater or bathroom heater plugged in, then this is a mystery.

Turning OFF the water heater, unless the previous owner did something really unique (spelled STUPID) should have NO IMPACT on the inverter.  The inverter was only originally wired to two circuits….microwave and the GFCI receptacle. 

NOW….this is where we, the site staff, get nervous as well as concerned about offering trouble shooting advice.

There is ONE simple, or at least in our opinion, trouble shooting attempt. Disconnect from SHORE. Disconnect one terminal (positive) on the back of the inverter. Disconnect the solar.  Turn off the breaker on the generator.  That removes all potential power.  Remove the plate or cover on the Magnum.  It is near where the AC cables come in. Refer to the Magnum Manual or download one.

There will be three cables.  One is INCOMING power and the other TWO is OUTGOING voltage.  They are labeled.  Use a screwdriver and tighten every terminal that has a wire attached.  Each cable will have a White & Black and Solid (ground).  Tighten the connections.  If one leg or wire was loose. It will heat up and arc. The current will spike and the pin circuit breaker will trip.

Then replace the cover….push and hold each pin breaker in, maybe pull out and cycle a few times.  The power from the 30 amp is split into TWO circuits.  Each one goes to the internal ATS or the relay on the board.  As long as there is incoming power and a good battery bank, the relay is closed and there is power coming out of the relay.  Each line or leg is connected to a circuit breaker…..then the circuit breaker output goes to the OUTGOING Power terminal.

Having a full load, on a totally different main panel circuit breaker (water heater), in NO WAY should trip an internal pin circuit breaker.

BUT….if some enterprising individual ran two circuits off the INV Line 1 (like putting Four Cables) into the inverter….then that would definitely overload it.

Put it all back together. If it still trips, I am reluctant to offer help as I, nor any other member, has NO IDEA if someone added an additional circuit or device or receptacle to the INV Line 1. Cable.  It COULD have been done downstream.  

The ONLY OTHER trouble shooting step.  Turn OFF the main Inverter breaker on the Main panel. Then test every electrical device.  The ONLY thing (circuits) NOT WORKING should be the receptacles and the microwave. If the water heater doesn't work, then the MH’s circuits have been modified and then troubleshot and returned to the original prints and configuration.

That’s it. One has to understand the logic and the circuitry and then troubleshoot…..otherwise, call a professional as we, staff and members, can NOT advise what to do without testing and verifying circuits and prints.

[laurice@email.com]

This is excellent. Thank you. 

Now I understand the system much better.  

Will let you know if any of the screws are loose etc. Other than that I believe that your suggestion will resolve the issue.  The system has worked flawlessly since last evening.  Being naturally lazy at least with the outside temperature where it is I'm hoping not to have to troubleshoot till the weather cooperates a bit more!  

Once again thanks for your wisdom and willingness to share Much appreciated