Routine maintenance on HVAC save you $12,000

[capwizard]

Re: Routine maintenance on HVAC save you $12,000

Thank you.

Understanding HVAC Schematics - 1
https://www.youtube.com/watch?v=fxwFzhaZmgY

[sam_sam_sam]

Re: Routine maintenance on HVAC save you $12,000

Where is the path for the 120 volts to go through the winding and then where ?
Any way the winding would over heat and burn out at full current
The biggest reason for putting one pole contacter is cheapness
I would rather pay $5.00 more for quality any day of week

[srhofmann]

Re: Routine maintenance on HVAC save you $12,000

The reason they use a single pole contactor is two fold, first, and foremost, it is cheaper. However, in theory, it saves them from having to furnish a crankcase heater for the compressor by applying 120 volts across the motor windings of the compressor, keeping the oil warm that is in the crankcase.

Now you know.....the REST of the story!

100% Correct. Really common in GE and Tranes. Replacing a single pole with a double pole contactor can cause damage to the compressor on startup when the compressor oil foams from the freon in the oil causing bearing failure. If you're that concerned with replacing the contactor then you should also put in a temperature controlled belly band crankcase heater to keep the compressor at least 10 degrees warmer than ambient air temperature.

[capwizard]

Re: Routine maintenance on HVAC save you $12,000

Quick way to measure system air flow using fan curve
https://www.youtube.com/watch?v=Z__6Tr84Gig