How much to clean a central A/C condenser??

[Bill Dufour]

Those cheap open type are called "definite purpose relay". I think meaning it must be enclosed for safety and only one amp rating no adjust ability like a contactor with overloads.
Just read an interesting article claiming washing a coil does no good unless it is caked with dirt/dust restricting airflow. Cleaning by itself may even reduce efficiency Some dust causes turbulent airflow and improves heat transfer. The opposite of a dust collector where you want laminar airflow for maximum flow rate. Maybe add vortex sheaders to improve coil efficiency?
Bill D.

[Lee DeRaud]

Those cheap open type are called "definite purpose relay". I think meaning it must be enclosed for safety and only one amp rating no adjust ability like a contactor with overloads.

Not sure I understand your point. The 'contactors' in the three AC compressors I've had were/are all (1) cheap, (2) open, and (3) non-adjustable.
(Not sure exactly how much current they carry, but it's certainly more than one amp.)

[Jim Koepke]

A simple search of > contactor vs relay < brought this comparison > https://www.electgo.com/difference-r...nd-contactors/

In the world of human communication people are likely to call a relay a contactor and a contactor a relay.

Sometimes a large relay may control a contactor and often a contactor may have an auxiliary circuit to energize a relay connected to an annunciator.

jtk

[Brian Elfert]

I dont mean to offend, but why would you let them do the work without agreeing on a price?

Absolutely my fault for not getting a set price ahead of time. I made the appointment more than a month ago, but I recall asking about the cost and she said it was time and materials. It was stupid of me not to ask how much the time cost. As it turns out they seem to have a flat rate for using chemicals to clean an A/C coil. The invoice shows an item called "chemclean" for $329. No trip charge or anything else.

[Bruce Wrenn]

Absolutely my fault for not getting a set price ahead of time. I made the appointment more than a month ago, but I recall asking about the cost and she said it was time and materials. It was stupid of me not to ask how much the time cost. As it turns out they seem to have a flat rate for using chemicals to clean an A/C coil. The invoice shows an item called "chemclean" for $329. No trip charge or anything else.

Did they include a LARGE jar of vasoline in the price?

[Bill Dufour]

Not sure I understand your point. The 'contactors' in the three AC compressors I've had were/are all (1) cheap, (2) open, and (3) non-adjustable.
(Not sure exactly how much current they carry, but it's certainly more than one amp.)

The one amp rating means they are only rated for a particular maximum ampacity. A motor controller has overloads that can be adjusted or swapped out to allow protection at various ampacities up to some maximum. If you need more amps you must swap in a different(usually physical larger) contactor/relay/motor controller.
Also a USA rated industrial relay will be rated for more lifetime cycles. A Din relay will often be rated for far less. Something like 500,00 vs 100,00. I suspect the cheapy ones are rated far less MTBF. If they are rated at all.
Bill D..

[Lee DeRaud]

The one amp rating means they are only rated for a particular maximum ampacity.

Ah, "one amp-rating", not "one-amp rating".

If I'm reading all this correctly, the widgets in the AC are really relays, not contactors, give or take some overlap/ambiguity.
But methinks it's one of those "if we slap some jargon on it, we can charge more" deals.

[lowell holmes]

competitive bids?

[Jim Koepke]

Maybe the high charge is because they most customers will watch and then do it themselves, never calling again unless something major fails.

jtk

[Rollie Meyers]

Flat rate pricing is a great money makers for contractors & no Vaseline® is provided. Unfortunately most HVAC contractors have gone flat rate as have plumbers, caps, & definite purpose contactors are cheap, but DP contactors are designed to be cheap, with no serviceable parts, just toss them away & replace them, cheap is one reason it is common to use a single pole DP contactor in single phase applications, & a 2 pole contactor for 3 phase, BTW it is code compliant to do it that way.

[Lee DeRaud]

Maybe the high charge is because they most customers will watch and then do it themselves, never calling again unless something major fails.

Maybe if they charged a reasonable price for a trivial repair they'd get repeat business.

If someone tries to rip me off on a small job, there's no way I'll call them back for a big one.

[Cary Falk]

I clean mine with a $8 can of Webb coil cleaner. Remove the skins. Spray it on and wait about 5 minutes and then hose it off. It is amazing how well it removes dog hair, dirt, dryer lint, etc.