DIY Home Improvement Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter · #1 ·
Need Electrical Help On Lennox AC
I have a Lennox 14ACX 3 ton AC unit. I purchased a crankcase heater (93M05) and a hard start kit (88M91).

Crankcase Heater
The schematic on in the manual shows a thermostat for the heater, but, I do not know if this is a separate part or if it is built into the heater assembly. I can not tell by looking at the heater assembly. The 93M05 is an option, but, no extra heater thermostat is listed. Also, there was no install instructions for the crankcase heater. Can anyone help? Photos?

Hard Start Kit
My second problem is that I find the enclosed install instructions confusing and contradictory. The schematic they provided only shows the terminal number of the potential relay on the sticker label and it does not seem to match wire color codes as they delivered this unit. Does anyone have better instructions or photos of this installation?

Thanks in advance.
 

·
Hvac Pro
Joined
·
23,688 Posts
Cannot seem to find a diagram of that setup on DaveNet. Usually a tech can figure it out on the job. Why do you need a heater and hard start kit when you do not live in a cold climate? Usually they are meant for where I live and for commercial apps where they try use it when it is less than 50 deg F outside. Anything higher than that and you don't need it.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #3 ·
Cannot seem to find a diagram of that setup on DaveNet. Usually a tech can figure it out on the job. Why do you need a heater and hard start kit when you do not live in a cold climate? Usually they are meant for where I live and for commercial apps where they try use it when it is less than 50 deg F outside. Anything higher than that and you don't need it.

I decided to return the crankcase heater. My compressor has a very loud start up some of the time and is right outside my bedroom window. I already installed the Lennox sound blanket over the compressor, helped some, but not enough. Had the refrigerant checked, input voltage and current at start up, all okay. Does not do it all the time. I was getting desperate so I thought I would try these. The crankcase heater is less likely to help. I am somewhat disappointed in the available documentation and Lennox support on this stuff. I am an electrical engineer and I am still having trouble sorting this out.

Thanks for your response.

Mike
 

·
Hvac Pro
Joined
·
23,688 Posts
That is not the quietest of their units at the best of times. The XC series is a lot quieter. Try put it on rubber corrugated vibrasorb pads from a refrigeration wholesaler. There is a accessory kit which has some vibration dampening weights which can be put on the suction line by the compressor. Comes as standard on the deluxe XC17 unit. Not sure what the part # is as I get them free from Lennox as a warranty part. VERY rare that I need them but a few over sensitive light sleeping customers I have used them for. Make sure the freon lines do not touch the house where they pass thru the foundation/wall and use silicone for the hole to prevent vibration transfer. All these little bits add up to a quieter install.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #5 ·
That is not the quietest of their units at the best of times. The XC series is a lot quieter. Try put it on rubber corrugated vibrasorb pads from a refrigeration wholesaler. There is a accessory kit which has some vibration dampening weights which can be put on the suction line by the compressor. Comes as standard on the deluxe XC17 unit. Not sure what the part # is as I get them free from Lennox as a warranty part. VERY rare that I need them but a few over sensitive light sleeping customers I have used them for. Make sure the freon lines do not touch the house where they pass thru the foundation/wall and use silicone for the hole to prevent vibration transfer. All these little bits add up to a quieter install.
Yes, I have the contractor Merit series, no choice on new home build. I also considered moving my current unit and even upgrading to the XC series, but both are a lot of money. When the unit is running, it is quiet enough, it is just the start up. The link below is what I recorded.

http://www.youtube.com/watch?v=MAdtYTc3V2I

In the meantime, we use a small fan in our bedroom for white noise and I turned up the speed.
 

·
Hvac Pro
Joined
·
23,688 Posts
Lots of them do that. Has to do with the sound of a Scroll compressor. The old reciprocating ones were a LOT quieter. Not sure if the spec for the quality of that compressor is the same as the more expensive XC series. Yours has a 5 yr warranty and the XC has a 10 yr warranty. Not much you can do about that sound.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #7 ·
Lots of them do that. Has to do with the sound of a Scroll compressor. The old reciprocating ones were a LOT quieter. Not sure if the spec for the quality of that compressor is the same as the more expensive XC series. Yours has a 5 yr warranty and the XC has a 10 yr warranty. Not much you can do about that sound.
I am holding off on the crankcase heater and may return it. I installed the hard start kit this morning and so far, the start up is no louder than the run noise, but, I need to observe it for a few days as the start up noise was somewhat random. I should check the start up current, as it usually reduces with the hard start kit. I would think that the higher the start up current, the louder the start up noise. I will let you know in a few day.
 
1 - 7 of 7 Posts
Top