Lee Smith Posted October 5, 2022 Posted October 5, 2022 I just replaced my front TV with a 50" flat screen Samsung. When I went to plug the TV into the lift controller box, I accidentally sparked the low voltage connector on the side of the controller. Here is a picture of the connector: Now my fold up/down electric lift is stuck down. I went to great lengths to remove the control board to find out who made it. Here is a picture: I found information on Tri Metal Fabrication, Inc but they are long out of business and the phone numbers and emails do not work. The former President was Mike McCormick in Eugene, Oregon.Does anyone have an electrical diagram for the Tri Metal Fabrication fold down lift? Or a parts source? I was able to verify that there is 110v power to the control board and the start capacitor tested good. Also, the various green control lights on the controller appear to be all lit. There are two limit switches. when pushed down, the switch on the right will cause a red light to come on at the controller and will test 28 volts at the connector. When pushed down, the one on the left does not turn a red light on but will test 28 volts at the connector, Here is a picture: Unless I can find a way to trouble shoot and fix, I am thinking I will straight wire and bypass the control board. I can fish an extension cord to the TV cabinet over the passenger seat for TV power. Of course, the motor could be bad. I should be able to straight wire the motor to test it without removing it. I can add a two-way momentary switch for up and down that works by reversing the polarity which changes the motor direction. I have tried to be clear but as you may have noted, this is all very new to me. Thanks in advance for any help you can give. Lee Smith
DavidL Posted October 5, 2022 Posted October 5, 2022 Looks like a PCB trace got smoked. Should be easy fix. Possibly some components along with it. Can you remove the PCB? Ship it to an electronics hobbyist.
Lee Smith Posted October 5, 2022 Author Posted October 5, 2022 Sorry to be ignorant but what is a PCB trace? I can easily remove the control board as I have already removed and opened the control board aluminum box enclosure. Do you have any ideas on how to find an electronics hobbyist? Thank you for your help.
Paul J A Posted October 5, 2022 Posted October 5, 2022 34 minutes ago, Lee Smith said: I just replaced my front TV with a 50" flat screen Samsung. When I went to plug the TV into the lift controller box, I accidentally sparked the low voltage connector on the side of the controller. Here is a picture of the connector: Now my fold up/down electric lift is stuck down. I went to great lengths to remove the control board to find out who made it. Here is a picture: I found information on Tri Metal Fabrication, Inc but they are long out of business and the phone numbers and emails do not work. The former President was Mike McCormick in Eugene, Oregon.Does anyone have an electrical diagram for the Tri Metal Fabrication fold down lift? Or a parts source? I was able to verify that there is 110v power to the control board and the start capacitor tested good. Also, the various green control lights on the controller appear to be all lit. There are two limit switches. when pushed down, the switch on the right will cause a red light to come on at the controller and will test 28 volts at the connector. When pushed down, the one on the left does not turn a red light on but will test 28 volts at the connector, Here is a picture: Unless I can find a way to trouble shoot and fix, I am thinking I will straight wire and bypass the control board. I can fish an extension cord to the TV cabinet over the passenger seat for TV power. Of course, the motor could be bad. I should be able to straight wire the motor to test it without removing it. I can add a two-way momentary switch for up and down that works by reversing the polarity which changes the motor direction. I have tried to be clear but as you may have noted, this is all very new to me. Thanks in advance for any help you can give. Lee Smith Contact https://eliternr.com/ or There are 4 service centers in the USA I have had success with, who specialize in Monaco/HR/Beaver coaches - Elite Renovation & Repair in Oregon, Executive Motor Coach in Vegas, Iron Horse RV in San Antonio, and Elkhart Sales & Service in Indiana. Give them a call. Reply Reply All Forward 1
Gary Cole Posted October 5, 2022 Posted October 5, 2022 (edited) Lee I would hardwire without question. I wouldn't waste anytime with unsupported, always obscenely overpriced, components. Two momentary pushbutton switches in order to reverse the motor. Or a 2 throw switch if you preferred. Forget about the limit switches as they are most certainly 1P and could not be wired in a 3 way configuration without using latching relays. Small dc motors are very tolerant of stalled rotor conditions. If you are concerned about the gear mechanism then experiment with an inline fuse that blows at some small amount of current above normal load in case you go to sleep on the push button. An automatically resetting dc breaker would be even more convenient. Very inexpensive. Edited October 5, 2022 by Gary Cole 1
bpperk Posted October 6, 2022 Posted October 6, 2022 I’m trying to track down my previously owned coach. When did you purchase your signature?
Lee Smith Posted October 6, 2022 Author Posted October 6, 2022 3 hours ago, bpperk said: I’m trying to track down my previously owned coach. When did you purchase your signature? March 2022. Bought from the 2nd Owner in Canada. 1st owner was from Tennessee. 3 hours ago, Gary Cole said: Lee I would hardwire without question. I wouldn't waste anytime with unsupported, always obscenely overpriced, components. Two momentary pushbutton switches in order to reverse the motor. Or a 2 throw switch if you preferred. Forget about the limit switches as they are most certainly 1P and could not be wired in a 3 way configuration without using latching relays. Small dc motors are very tolerant of stalled rotor conditions. If you are concerned about the gear mechanism then experiment with an inline fuse that blows at some small amount of current above normal load in case you go to sleep on the push button. An automatically resetting dc breaker would be even more convenient. Very inexpensive. Thanks for the advice. The motor is 115v 2.7A 1/4 hp ac. It has an ac capacitor. The capacitor is wired directly into the controller circuit board. How can I wire it directly? Here is a picture of the capacitor:
Gary Cole Posted October 6, 2022 Posted October 6, 2022 (edited) Lee I assumed you had a DC motor. AC is a little more complicated. If the motor reverses, which I assume it does because it terminates on the board, then you have to reverse the polarity of the start capacitor using a 1P/2T switch in order to change the rotation of the motor. Your control board was doing that. Also AC motors are not tolerant of a locked rotor condition. So its necessary that you keep your limit switches. The limit switches are going to be a problem unless they are 1P/2T. I'm guessing that they are not. If not then you are going to be required to use latching relays if you elect to keep the 1P limit switches. It is certainly a doable project if you decided to get into it that deep. Edited October 6, 2022 by Gary Cole
Ivan K Posted October 6, 2022 Posted October 6, 2022 Polarity of an AC capacitor? Or flipping the start winding? Either way, the AC motor certainly makes it more complicated for an RV use than needed to be.
Lee Smith Posted October 6, 2022 Author Posted October 6, 2022 3 hours ago, Ivan K said: Polarity of an AC capacitor? Or flipping the start winding? Either way, the AC motor certainly makes it more complicated for an RV use than needed to be. Ivan, that is a great opinion. After three days trying to solve my overkill fold down TV, I am ready to keep the mechanical side but switch the electrical motor and wiring system to DC. I will try one more solution this morning and if this does not work I will make the switch to DC. In that regard, I found what appears to be a well-made "do it yourself" fold down DC design online: Motorized Flip Down TV Lift : 7 Steps (with Pictures) - Instructables Here is the design schematic and a sample wiring picture: I do not believe that this will be complicated or expensive. I intend to fully re-use the mechanical lift components so the end product will look the same. There is already DC power to the unit for the control board and the stop limit switches that is fused in the front run box. There is also 110 AC, but I will probably run an extension cord back to the original console location above the passenger seat. One thing I will do, as suggested in this DIY writeup, is to add two direct DC wired accessible wire connection posts in order to be able to raise the unit in an emergency situation. I would hate to have this unit stuck down while trying to leave an RV park. I will keep track and do a post on the results. However, it may be several weeks to get ready and order parts. In the meantime, I will remove the AC motor and temporarily raise the TV. 1
Gary Cole Posted October 6, 2022 Posted October 6, 2022 Ivan you are correct. Though some capacitors have polarity which must be observed. Here one is reversing one lead of the capacitor with the other lead of the winding with L1 and L2. The capacitor remains in series in the capacitor/winding circuit. Looks like an interesting project Lee. As to the schematic. Doesn't look like it is reversing the motor as drawn. Need to swap -/+ at one relay? 1 1
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