Home Air Conditioner unit grounding .. any fix?
 

Hello everyone,

Monday night our AC unit (electric central air and heat) started making
a strange squeeling sound (like a loose belt on a car) then acted like
it was loosing power... going normal then slowing down then normal
again, etc. I turned it off and called a local repair shop which I've
used in the past.

They came out today, and after turning the break back on, the repair
guy touched the outside of the unit to get a shock which threw him back
a few feet -- he touched the outside of the unit, nothing internal.
After turning the power back off he did more digging and said the
compressor was grounding and either the compressor needed to be
replaced or the entire outside unit needed replacing.

This AC is about 23 years old and a 3 ton unit, and though we didn't
expect to spend the money now, we hoped to upgrade to a larger unit at
some point as we hoped to convert our garage into another room within
the next year.

Just thought I'd put this out there for others more experienced then I
to review. As I said, I've used this company before, and I have no
reason to not trust them... but before spending $3500 or more I just
like to do some digging.

Take care --

Alex

Home Air Conditioner unit grounding .. any fix?
 

Whatever else you do, have the wiring to the unit checked. There is supposed
to be a ground that should trip the breaker with a fault like that.

Home Air Conditioner unit grounding .. any fix?
 

On Wed, 18 Oct 2006 21:38:11 GMT, "Paul A" wrote:

Whatever else you do, have the wiring to the unit checked. There is supposed
to be a ground that should trip the breaker with a fault like that.


No.

There is no breaker on the ground and the actual breaker doesn't trip
on a bad ground. It trips on excessive current thru the hot wire
with the breaker on it and this situation is bad but it doesn't trip
breakers.

Home Air Conditioner unit grounding .. any fix?
 

Alex wrote:
Hello everyone,

Monday night our AC unit (electric central air and heat) started
making a strange squeeling sound (like a loose belt on a car) then
acted like it was loosing power... going normal then slowing down
then normal again, etc. I turned it off and called a local repair
shop which I've used in the past.

They came out today, and after turning the break back on, the repair
guy touched the outside of the unit to get a shock which threw him
back a few feet -- he touched the outside of the unit, nothing
internal. After turning the power back off he did more digging and
said the compressor was grounding and either the compressor needed to
be replaced or the entire outside unit needed replacing.

Huh?

There are two moving parts - that could cause a screeching noise - in the
outside unit: the compressor and the fan.

My bet is on the fan (a $300 item).

I'd have someone else have a look. It's customary, when a repairman doesn't
know what's wrong, to replace the whole thing.

You may just have a burnt wire...

Home Air Conditioner unit grounding .. any fix?
 

Alex writes:

Just thought I'd put this out there for others more experienced then I
to review.

The proferred diagnosis is consistent with what you've described. You've
gotten your money's worth and more out of a 23-year-old unit, and it's time
to replace.

You can search grainger.com to see what these units really cost
uninstalled.

Home Air Conditioner unit grounding .. any fix?
 

Alex wrote:
Hello everyone,

Monday night our AC unit (electric central air and heat) started
making a strange squeeling sound (like a loose belt on a car) then
acted like it was loosing power... going normal then slowing down
then normal again, etc. I turned it off and called a local repair
shop which I've used in the past.

They came out today, and after turning the break back on, the repair
guy touched the outside of the unit to get a shock which threw him
back a few feet -- he touched the outside of the unit, nothing
internal. After turning the power back off he did more digging and
said the compressor was grounding and either the compressor needed to
be replaced or the entire outside unit needed replacing.

This AC is about 23 years old and a 3 ton unit, and though we didn't
expect to spend the money now, we hoped to upgrade to a larger unit at
some point as we hoped to convert our garage into another room within
the next year.

Just thought I'd put this out there for others more experienced then I
to review. As I said, I've used this company before, and I have no
reason to not trust them... but before spending $3500 or more I just
like to do some digging.

Take care --

Alex

At 23 years old, my vote it to replace it with a modern more efficient
model. In the long run it is likely to be less expensive to do it that
way.

--
Joseph Meehan

Dia duit

Home Air Conditioner unit grounding .. any fix?
 

No.

There is no breaker on the ground and the actual breaker doesn't trip
on a bad ground. It trips on excessive current thru the hot wire
with the breaker on it and this situation is bad but it doesn't trip
breakers.







With a good ground (which is missing) the breaker on the hot wire(s) will
likely trip
on the short to the case that gave the guy the shock. (depending on the
restance of the short)

In any case, with a proper ground there would be no shock.

Home Air Conditioner unit grounding .. any fix?
 

DK wrote:
On Wed, 18 Oct 2006 21:38:11 GMT, "Paul A" wrote:

Whatever else you do, have the wiring to the unit checked. There is supposed
to be a ground that should trip the breaker with a fault like that.


No.

There is no breaker on the ground and the actual breaker doesn't trip
on a bad ground. It trips on excessive current thru the hot wire
with the breaker on it and this situation is bad but it doesn't trip
breakers.

And again the reason it did not trip the breaker is that a required
Equipment Grounding Conductor is open or missing. The EGC, if present
and intact, will fault out the circuits Over Current Protective Device
(OCPD) by conducting the stray current back to the source so that the
OCPD opens. In a properly wired and maintained unit that would happen
the moment the fault occurred.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison