2004 Harman Accentra Insert Low voltage coming off new control board

mrbgrant

Member
Jan 25, 2018
25
massachusetts
Sorry to bother the team i needed a little help, i purchased an old Harman Accentra Insert for Rehab, the project has gone nicely...i have replaced most of the major components. I bench tested each component and everything has been working fine...….but my exhaust/combustion motor will not run when i start the unit up. I bench tested it again at 120V and it works great....finally i noticed that my brand new control board is only providing 94V to the blower.

If anyone has any ideas i would greatly appreciate it.
Thank you
 

Former Farmer

Feeling the Heat
Apr 12, 2008
499
NE Wisconsin
Does the control board provide both the hot and the neutral to the motor? Did you check the voltage from the hot wire to ground at the motor? I think that you either have a bad neutral at the motor connection or a bad control board. If it is a new board, it should be covered under warranty.
 

mrbgrant

Member
Jan 25, 2018
25
massachusetts
Thank you for the input. The 94 volts was tested right at the control board. i agree that it is probably a bad control board. i was hoping that there was and adjustment that i missed. i analyzed the dip switches last night but none control the exhaust/combustion blower. Thanks again. I will call the sales tech service on Tuesday and follow up here with an answer.
 

Montecarlossfan

New Member
Jan 1, 2019
51
Connecticut
I do know that the draft adjustment pot will vary voltage to the combustion blower on low speed , but I believe a 120v motor should run at 94v , must not be providing the proper current, the combustion blower will run slower at low burn and faster or max at higher burn rates.
 
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mrbgrant

Member
Jan 25, 2018
25
massachusetts
I do know that the draft adjustment pot will vary voltage to the combustion blower on low speed , but I believe a 120v motor should run at 94v , must not be providing the proper current, the combustion blower will run slower at low burn and faster or max at higher burn rates.
Thanks you so much, i can bench test the combustion blower at various volt levels. i appreciate that. Also i am going to check the output from the board more carefully to see if there are any issues that i over looked.
 

rickwai

Minister of Fire
Nov 1, 2011
745
ohio
Put it in test mode. That should send full power. At start up that is about what it sends to comb. motor
 

mrbgrant

Member
Jan 25, 2018
25
massachusetts
I
Yes the motor should run @ 80vac and up.
Put it in test mode. That should send full power. At start up that is about what it sends to comb. motor
I wanted to thank the team for the responses. I believe that I have multiple issues going on with my stove rebuild. The exhaust blower was an aftermarket blower manufactured by NGK and is not longer sold but my local parts store....it is clearly not starting at 94V (which is what the board is putting out, but running at 120V when bench tested).

Most importantly my brand new Harman board is not putting out anything more than 94V. The "Potentiometer" (used for adjusting Draft (exhaust/combustion blower voltage)) on the board is supposed to be factory preset at 120V (from what I can find), but it is already maxed out at 94.

i'll keep you posted with the final outcome...my parts store tech service guy stated that he will test my board by putting it in another Harman stove and see if the stove works....he really did not seem well versed in testing the voltage output of a control board (I am no genius at this either).

Thanks again
 

ABusWrench

Member
Sep 11, 2015
86
East Canton, Ohio
Okay, read this over twice. Could there be a grounding issue? Would cause voltage issues. Also, is the board truly getting 120 volts? Check both sides of the plug where it attaches to the board. Good luck.
 

mrbgrant

Member
Jan 25, 2018
25
massachusetts
Thank you everyone for the assistance. The mission is complete. The culprit seems to have been a bad neutral wire on the new wiring harness. I went through the stove last night. cleaned up the grounds. Finally I installed the original wiring harness and she fired right up.

I wanted to take a moment to thank you all. Over the past few years I have been switching out my old pellet stoves for these more fancier models. The forum has proved to be invaluable to my effort. Thanks Again for your support.