Home » Public Forums » GMCnet » HVAC gauges and capacitors
| HVAC gauges and capacitors [message #87111] |
Thu, 03 June 2010 11:48  |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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What gauge set can I purchase to use on my GMC air conditioning that would also work on r22? Where would you buy them? I understand that it would be illegal for a non-licensed person to install r22.
Do 115 volt ac motor run capacitors have reduced capacity over time or are they either good or bad? How would you test a run capacitor?
Here is a background story on why I am asking...
Summer is coming too early so we wanted to have our home HVAC systems checked. I have always prefered to do my own home maintenance but I don't have any real ac skill and expected they might be low on freon. The technician from one of the best rated HVAC companies locally arrives to complete "17 point inspection and coil cleaning". Going to the inside air handlers he immediately pulls the run capacitor for the furnace fan and tells me it is rated for 10 microfarads, reads only 6.5 on his meter, and if it goes out it will probably ruin my expensive 3/4 hp furnace motor. Our other unit has a 7.5 capacitor, which reads 5.6. Back to his truck where he produces his price book and shows me the list price for each capacitor is $251.00, which he can discount by $25 -- and then offers to call the company owner who may be able to drop another $25 -- now about $200 -- and I need two. Standing there, either dumbfounded or possibly with a dumb look on my face -- I decline while he again tells me if it fails I might lose my $820 3/4 hp motor, as he points to his price book. Now on to the outside unit where he checks the freon level, suggests it is one lb low. I am braced for the cost -- freon is $115 for the first lb and $39 for each additional. He says the dual run capacitor checks ok. Same story for the other outside unit. Most of the time he was on site he was on the phone -- or telling me about air cleaners, new systems (mine are 12 years old), or $265 freon leak tests.
Final bill, $341, $74 per unit for the inspection and outside coil cleaning, and $193 for three lb of freon.
As I watch him leave, he runs into a large planter on the driveway but he doesn't bother to stop.
Do I really need new capacitors? Well, since I am not positive, I use my GMCnet training,go to McMaster-Carr, order the run capacitors for about $6 each plus $5 shipping -- $17 total -- saving $383.
Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] HVAC gauges and capacitors [message #87120 is a reply to message #87111] |
Thu, 03 June 2010 13:18  |
emerystora
Messages: 4442
Registered: January 2004
Karma: 13
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Senior Member |
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You can listen to the motor start and as long as it is not hesitating and humming a lot before starting then you don't need to change the capacitors.
I would send the company a bill for the planter he ran over!
Most gauge sets that are used for automotive R12 also have a scale for R22. You can easily find them on the Internet or probably at Harbor Freight.
It is not illegal to work on your own system. It is illegal for an unliscensed person to work for hire on someone's system.
Emery Stora
On Jun 3, 2010, at 10:48 AM, Dennis Sexton wrote:
>
>
> What gauge set can I purchase to use on my GMC air conditioning that would also work on r22? Where would you buy them? I understand that it would be illegal for a non-licensed person to install r22.
>
> Do 115 volt ac motor run capacitors have reduced capacity over time or are they either good or bad? How would you test a run capacitor?
>
> Here is a background story on why I am asking...
>
> Summer is coming too early so we wanted to have our home HVAC systems checked. I have always prefered to do my own home maintenance but I don't have any real ac skill and expected they might be low on freon. The technician from one of the best rated HVAC companies locally arrives to complete "17 point inspection and coil cleaning". Going to the inside air handlers he immediately pulls the run capacitor for the furnace fan and tells me it is rated for 10 microfarads, reads only 6.5 on his meter, and if it goes out it will probably ruin my expensive 3/4 hp furnace motor. Our other unit has a 7.5 capacitor, which reads 5.6. Back to his truck where he produces his price book and shows me the list price for each capacitor is $251.00, which he can discount by $25 -- and then offers to call the company owner who may be able to drop another $25 -- now about $200 -- and I need two. Standing there, either dumbfounded or possibly with a dumb look on my face -- I decline while he again
t
> ells me if it fails I might lose my $820 3/4 hp motor, as he points to his price book. Now on to the outside unit where he checks the freon level, suggests it is one lb low. I am braced for the cost -- freon is $115 for the first lb and $39 for each additional. He says the dual run capacitor checks ok. Same story for the other outside unit. Most of the time he was on site he was on the phone -- or telling me about air cleaners, new systems (mine are 12 years old), or $265 freon leak tests.
>
> Final bill, $341, $74 per unit for the inspection and outside coil cleaning, and $193 for three lb of freon.
>
> As I watch him leave, he runs into a large planter on the driveway but he doesn't bother to stop.
>
>
> Do I really need new capacitors? Well, since I am not positive, I use my GMCnet training,go to McMaster-Carr, order the run capacitors for about $6 each plus $5 shipping -- $17 total -- saving $383.
>
>
>
>
>
>
> --
> Dennis Sexton
> 73 Painted Desert 230
> Germantown, TN
> _______________________________________________
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Emery Stora
77 Kingsley
Santa Fe, NM
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| Re: [GMCnet] HVAC gauges and capacitors [message #87127 is a reply to message #87120] |
Thu, 03 June 2010 14:39 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Emery et al,
The motors seem to start without hesitation -- will a weak run capacitor cause the motor to operate at any lower rpm or with less capability to push air through the system?
I have now looked at a few gauge sets on-line. One seller made reference to minimal loss connectors that might prevent frost-bite. Any experience?
There appear to be limitations to buying r22 without some form of EPA certification.
Thank you.
Dennis Sexton
73 GMC
Germantown, TN
USA
-----Original Message-----
From: Emery Stora <emerystora@mac.com>
To: gmclist@temp.gmcnet.org
Sent: Thu, Jun 3, 2010 1:18 pm
Subject: Re: [GMCnet] HVAC gauges and capacitors
You can listen to the motor start and as long as it is not hesitating and
umming a lot before starting then you don't need to change the capacitors.
I would send the company a bill for the planter he ran over!
Most gauge sets that are used for automotive R12 also have a scale for R22. You
an easily find them on the Internet or probably at Harbor Freight.
t is not illegal to work on your own system. It is illegal for an unliscensed
erson to work for hire on someone's system.
Emery Stora
On Jun 3, 2010, at 10:48 AM, Dennis Sexton wrote:
>
What gauge set can I purchase to use on my GMC air conditioning that would
lso work on r22? Where would you buy them? I understand that it would be
llegal for a non-licensed person to install r22.
Do 115 volt ac motor run capacitors have reduced capacity over time or are
hey either good or bad? How would you test a run capacitor?
Emery Stora
7 Kingsley
anta Fe, NM
______________________________________________
MCnet mailing list
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ttp://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] HVAC gauges and capacitors [message #87128 is a reply to message #87121] |
Thu, 03 June 2010 14:49 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Charles,
Well, it would cost more than $350 to replace it -- it is one of a matching pair that flank the entrance of the drive -- fortunately his truck only pushed it about 8 inches down the drive before he stopped, pulled forward and backed out differently. But then he just drove off. Had it caused more damage -- I would be putting a stop on my card payment -- "she" would be planning revenge.
Dennis
-----Original Message-----
From: Charles <gcw13@sbcglobal.net>
To: gmclist@temp.gmcnet.org
Sent: Thu, Jun 3, 2010 1:50 pm
Subject: Re: [GMCnet] HVAC gauges and capacitors
Dennis,
hat was a $341.00 planter, wasn't it?
harles
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] HVAC gauges and capacitors [message #87134 is a reply to message #87127] |
Thu, 03 June 2010 16:09 |
emerystora
Messages: 4442
Registered: January 2004
Karma: 13
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Senior Member |
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On Jun 3, 2010, at 1:39 PM, dennisfsexton@aol.com wrote:
>
> Emery et al,
> The motors seem to start without hesitation -- will a weak run capacitor cause the motor to operate at any lower rpm or with less capability to push air through the system?
>
The capacitors are only there to give it a little "boost" when starting to turn the motor. They will not affect the operation of the motor once it starts.
> I have now looked at a few gauge sets on-line. One seller made reference to minimal loss connectors that might prevent frost-bite. Any experience?
>
You can also just use these with any gauge set:
I bought them at the first air conditioning supply store I went to in Albuquerque.
They are called Thumbscrew Core Depressors. They prevent loss of gas when removing the hoses.
Here are some on the internet
http://www.hvacr-tools.com/mm5/merchant.mvc?Screen=PROD&Store_Code=HVACR&Product_Code=CD5050&Category_Code=COREREMOVALTOOLS
That is actually less than I paid for them.
You can probably find a lot of sites that sell them.
> There appear to be limitations to buying r22 without some form of EPA certification.
Yes, just like R12, you need a certification to buy it -- or anyone with a business license in a state can buy it.
If you have a friend that has a store or other business you could use his tax number to give when you purchase it.
When you order over the net you just have to give them a state tax id number or a business number.
You would probably have to order about a 30# container of R22 which is going to be a whole lot more than you will need in a lifetime of topping up your home air conditioner.
As a suggestion why don't you consider using HC22a. This is similar to the HC12a that many are putting into our motorhomes but it is used where R22 is.
Check out http://www.foxtoolsupply.com/
You don't need any license to buy it and it is compatible with R22 in an air conditioning system. So, you could top up with it, or you could consider vacuuming out all of the R22 and replacing it with HC22a.
Emery Stora
>
> Thank you.
>
>
> Dennis Sexton
> 73 GMC
> Germantown, TN
> USA
>
>
>
> -----Original Message-----
> From: Emery Stora <emerystora@mac.com>
> To: gmclist@temp.gmcnet.org
> Sent: Thu, Jun 3, 2010 1:18 pm
> Subject: Re: [GMCnet] HVAC gauges and capacitors
>
>
> You can listen to the motor start and as long as it is not hesitating and
> humming a lot before starting then you don't need to change the capacitors.
> I would send the company a bill for the planter he ran over!
> Most gauge sets that are used for automotive R12 also have a scale for R22. You
> an easily find them on the Internet or probably at Harbor Freight.
> It is not illegal to work on your own system. It is illegal for an unlicensed
> person to work for hire on someone's system.
> Emery Stora
> On Jun 3, 2010, at 10:48 AM, Dennis Sexton wrote:
>>
>
> What gauge set can I purchase to use on my GMC air conditioning that would
> also work on r22? Where would you buy them? I understand that it would be
> illegal for a non-licensed person to install r22.
>
> Do 115 volt ac motor run capacitors have reduced capacity over time or are
> hey either good or bad? How would you test a run capacitor?
>
>
> Emery Stora
> 7 Kingsley
> anta Fe, NM
>
> ______________________________________________
> MCnet mailing list
> ist Information and Subscription Options:
> ttp://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Emery Stora
77 Kingsley
Santa Fe, NM
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List Information and Subscription Options:
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| Re: HVAC gauges and capacitors [message #87155 is a reply to message #87111] |
Thu, 03 June 2010 18:28 |
Wander Inn
Messages: 100
Registered: January 2010
Location: Phoenix Az.
Karma: 0
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Senior Member |
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Dennis
If your unit needed freon there should be a leak somewhere,
I've seen people hookup gauges and pretend to put freon in.
If the unit was cooling before he worked on it, I dout
you had leak.
good luck
Mike
Mike & Chris Hughes
1977 Kingsley
Phoenix, Az.
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| Re: HVAC gages and capacitors [message #87160 is a reply to message #87111] |
Thu, 03 June 2010 18:52 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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|
Boy that is a new one on me I would stay away from that co. First off in 40 years as an a/c service mechanic I have never replaced a capacitor because the microfarids had changed?! The normal reason to change them would be for a shorted or open one.
I have changed them as a mater of course when replacing a new motor or compressor but in a lot of cases the new compressor or motor required a different microfarid then the old one and I wouldn't find out till I had the new parts so I would just get the whole setup. The easiest way for you to see if you need R22 in your system if you don't have a sight glass on your liquid line is to check the supply air in the duct a few feet down stream of the A coil after the unit has been running for about 15 minutes. It should be around 22 degrees colder then the air that is coming into the A coil(use the same thermometer). Also the suction line coming into the compressor should be cold . This is the method the idiot should have used if he were honest. As far as gages and manifold go I think harbor freight has a cheap set or the can be found at garage sales. 134A is supposed to be used with a different set then R22 or R12 but I just use the same Gage set with an adapter for the 134 valves. R22 can be found on Craig list or E bay.
Roy
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: [GMCnet] HVAC gauges and capacitors [message #87187 is a reply to message #87134] |
Thu, 03 June 2010 20:44 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
|
|
Emery,
Great! Thank you for the information on the hose fittings and on the HC22a.
I know we have had discussions on the flammability of HC12a, Duracool -- I see in some reading on HVAC forums that some raise big concerns about using HC22a in a system that has a gas furnace.
Dennis Sexton
73 GMC
Germantown, TN
USA
-----Original Message-----
From: Emery Stora <emerystora@mac.com>
To: gmclist@temp.gmcnet.org
Sent: Thu, Jun 3, 2010 4:09 pm
Subject: Re: [GMCnet] HVAC gauges and capacitors
n Jun 3, 2010, at 1:39 PM, dennisfsexton@aol.com wrote:
>
Emery et al,
The motors seem to start without hesitation -- will a weak run capacitor cause
he motor to operate at any lower rpm or with less capability to push air
hrough the system?
he capacitors are only there to give it a little "boost" when starting to turn
he motor. They will not affect the operation of the motor once it starts.
> I have now looked at a few gauge sets on-line. One seller made reference to
inimal loss connectors that might prevent frost-bite. Any experience?
ou can also just use these with any gauge set:
I bought them at the first air conditioning supply store I went to in
lbuquerque.
hey are called Thumbscrew Core Depressors. They prevent loss of gas when
emoving the hoses.
Here are some on the internet
ttp://www.hvacr-tools.com/mm5/merchant.mvc?Screen=PROD&Store_Code=HVACR&Product_Code=CD5050&Category_Code=COREREMOVALTOOLS
That is actually less than I paid for them.
You can probably find a lot of sites that sell them.
> There appear to be limitations to buying r22 without some form of EPA
ertification.
Yes, just like R12, you need a certification to buy it -- or anyone with a
usiness license in a state can buy it.
f you have a friend that has a store or other business you could use his tax
umber to give when you purchase it.
hen you order over the net you just have to give them a state tax id number or
business number.
You would probably have to order about a 30# container of R22 which is going to
e a whole lot more than you will need in a lifetime of topping up your home air
onditioner.
As a suggestion why don't you consider using HC22a. This is similar to the
C12a that many are putting into our motorhomes but it is used where R22 is.
Check out http://www.foxtoolsupply.com/
You don't need any license to buy it and it is compatible with R22 in an air
onditioning system. So, you could top up with it, or you could consider
acuuming out all of the R22 and replacing it with HC22a.
Emery Stora
Thank you.
Dennis Sexton
73 GMC
Germantown, TN
USA
-----Original Message-----
From: Emery Stora <emerystora@mac.com>
To: gmclist@temp.gmcnet.org
Sent: Thu, Jun 3, 2010 1:18 pm
Subject: Re: [GMCnet] HVAC gauges and capacitors
You can listen to the motor start and as long as it is not hesitating and
humming a lot before starting then you don't need to change the capacitors.
I would send the company a bill for the planter he ran over!
Most gauge sets that are used for automotive R12 also have a scale for R22.
ou
an easily find them on the Internet or probably at Harbor Freight.
It is not illegal to work on your own system. It is illegal for an unlicensed
> person to work for hire on someone's system.
Emery Stora
On Jun 3, 2010, at 10:48 AM, Dennis Sexton wrote:
>
What gauge set can I purchase to use on my GMC air conditioning that would
also work on r22? Where would you buy them? I understand that it would be
illegal for a non-licensed person to install r22.
Do 115 volt ac motor run capacitors have reduced capacity over time or are
hey either good or bad? How would you test a run capacitor?
Emery Stora
7 Kingsley
anta Fe, NM
______________________________________________
MCnet mailing list
ist Information and Subscription Options:
ttp://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Emery Stora
7 Kingsley
anta Fe, NM
______________________________________________
MCnet mailing list
ist Information and Subscription Options:
ttp://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Dennis S
73 Painted Desert 230
Memphis TN Metro
|
|
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| Re: [GMCnet] HVAC gages and capacitors [message #87189 is a reply to message #87160] |
Thu, 03 June 2010 20:51 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
|
Senior Member |
|
|
Roy,
Thank you for the benefit of your experience. Great thing about our GMC group is the breadth of life and work backgrounds.
I wanted to give the AC technician benefit of the doubt -- he did improve the cooling of the systems -- just hope he did it correctly. But I just felt like I was being misled.
I don't think I have an access that close to the discharge from the A coil. The suction line is cold and wet and the high pressure line is warm -- much greater differential than before.
It did sort of irritate me that he only offered a $265 leak check -- and didn't bother to try using a little soapy water on the connections or fill valve.
Thanks again,
Dennis
Dennis Sexton
73 GMC
Germantown, TN
USA
-----Original Message-----
From: roy keen <roynpaula@charter.net>
To: gmclist@temp.gmcnet.org
Sent: Thu, Jun 3, 2010 6:52 pm
Subject: Re: [GMCnet] HVAC gages and capacitors
Boy that is a new one on me I would stay away from that co. First off in 40
ears as an a/c service mechanic I have never replaced a capacitor because the
icrofarids had changed?! The normal reason to change them would be for a
horted or open one.
I have changed them as a mater of course when replacing a new motor or
ompressor but in a lot of cases the new compressor or motor required a
ifferent microfarid then the old one and I wouldn't find out till I had the new
arts so I would just get the whole setup. The easiest way for you to see if
ou need R22 in your system if you don't have a sight glass on your liquid line
s to check the supply air in the duct a few feet down stream of the A coil
fter the unit has been running for about 15 minutes. It should be around 22
egrees colder then the air that is coming into the A coil(use the same
hermometer). Also the suction line coming into the compressor should be cold .
his is the method the idiot should have used if he were honest. As far as gages
nd manifold go I think harbor freight has a cheap set or the can be found at
arage sales. 134A is supposed to be used with a different set then R22 or R12
ut I just use the same Gage set with an adapter for the 134 val
ves. R22 can be found on Craig list or E bay.
Roy
______________________________________________
MCnet mailing list
ist Information and Subscription Options:
ttp://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Dennis S
73 Painted Desert 230
Memphis TN Metro
|
|
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| Re: [GMCnet] HVAC gages and capacitors [message #87234 is a reply to message #87189] |
Thu, 03 June 2010 23:17 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
|
Senior Member |
|
|
If you were short of refrigerant even a pound or two it would be important that he found the leak or you get to do it again soon. Also a short charge costs you money as the compressor runs a lot more. If there is no place to stick a thermometer chose a room vent near the blower. I always used soap bubbles after I found the leak and after I fixed it to be sure. I hate call backs they are embarrassing.
Roy
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: [GMCnet] HVAC gages and capacitors [message #87431 is a reply to message #87234] |
Sat, 05 June 2010 18:04 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
|
Senior Member |
|
|
Roy and Emery,
Today I pulled the capacitors, tested them on my mulitmeter and installed the new ones (tested them too). Seemed like it mght be a reasonable precaution.
I will find a way to do the temperature drop test. I also think I may try to check the temperatures at the compressor on both the low and high side lines -- just as a baseline.
Thank you both again.
Dennis Sexton
73 GMC
Germantown, TN
USA
-----Original Message-----
From: roy keen <roynpaula@charter.net>
To: gmclist@temp.gmcnet.org
Sent: Thu, Jun 3, 2010 11:17 pm
Subject: Re: [GMCnet] HVAC gages and capacitors
If you were short of refrigerant even a pound or two it would be important that
e found the leak or you get to do it again soon. Also a short charge costs you
oney as the compressor runs a lot more. If there is no place to stick a
hermometer chose a room vent near the blower. I always used soap bubbles after
found the leak and after I fixed it to be sure. I hate call backs they are
mbarrassing.
Roy
______________________________________________
MCnet mailing list
ist Information and Subscription Options:
ttp://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Dennis S
73 Painted Desert 230
Memphis TN Metro
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