HVAC

Ask a HVAC Question, Get an Answer ASAP!

Have your own HVAC question?

3 HVAC Technicians are Online Now

characters left:

Not a HVAC Question?

Question

i have a carrier air conditioner installed in august 2004. i can hear the power source getting to
the unit, but it is not engaging the motor.

Submitted: 134 days and 1 hours ago.

Category: HVAC

Value: $18

Status: AWAITING CUSTOMER ACTION

Posted by Kenton Guidry 134 days and 1 hours ago.

Info Request

Does the indoor fan work?

What do you hear, and where do you hear it?

134 days and 1 hours ago.

Reply

yes the indoor fan is working

i have the panel off the outside unit and i can a humming or buzzing
noise near what i think is a silonoid looking part. a silver sphere shape that has three electrical connections on top

Accepted Answer

The silver sphere you are referring to is a capacitor. It should not have any noise coming from it.

Here is a link to what a capacitor looks like so that we can confirm that is what you are looking at.

http://www.mobilehomerepair.com/media/img/coleman/1498-5351.jpg

Usually if you hear a hum it is from the contactor. Here is a link to a contactor photo.

http://img.china.alibaba.com/img/offer/10/17/38/17/1/101738171

Can you tell me if the contactor is making the noise?

Can you also tell me if your breaker is tripped?

Accepts:
Expert:	Kenton Guidry
Pos. Feedback:	98.8 %
Answered:	7/12/2009

HVAC Technician

EPA issued refrigeration license, College certificate, and 7 years in field.

134 days and 1 hours ago.

Reply

i'm fairly sure the noise was from the capacitor, i will double check that.
i know that the inside breaker is not tripped, i cant tell about the one on the outside i've never seen a breaker like it before.

Posted by Kenton Guidry 134 days and 1 hours ago.

Answer

The outside may be a disconnect.

Here is a photo of a disconnect.

http://www.deanbennett.com/fuse-disconnect-box.gif

Here is another.

http://www.myhvacparts.com/Fused%20disconnect%20box%20closed.jpg

We need to find out if you have fuses inside the disconnect, or if there is a breaker in the disconnect.

Also, turn the thermostat to off. If the sound stops then the contactor is the culprit.

Please let me know if the sound stops and if you have either fuses, or a breaker outside at the disconnect.

134 days and 1 hours ago.

Reply

the sound stopped after i turned the thermostat to off.
i think the outside must be fuses, there is no breaker switch there.

Posted by Kenton Guidry 134 days and 1 hours ago.

Answer

Do you see fuses that look like the photo below? Your fuses will be larger than the photo example but will confirm that there are fuses.

http://help.hudsoncarpentry.co.uk/Images/Electrics/howTo/changeFuse/fusesFig1.jpg

The noise must be the contactor.

134 days and 1 hours ago.

Reply

i dont see the actual fuses, just the box with a about 2/12 in square black front the has a small metal pull ring hanging in front

Posted by Kenton Guidry 134 days and 1 hours ago.

Answer

This must be a non fused disconnect.

Can you turn your breaker to the condenser off, and then on.

Then have someone turn on the air conditioner while you stand outside to watch and hear it.

Let me know if it tries to start.

134 days and 1 hours ago.

Reply

the noise is at the contactor and at times the motor will buzz like it wants to start but doesn't

Posted by Kenton Guidry 134 days and 1 hours ago.

Info Request

Go ahead and leave the power off.

Does the fan located at the condenser ever come on?

134 days ago.

Reply

a/c power is off. the fan on the outside unit(is that the condenser?)
has not ever come on with or without power. the inside fan unit is still on now

Posted by Kenton Guidry 134 days ago.

Answer

That condenser fan (outside) should come on with your compressor.

You will have to get a technician out.

Your dual capacitor could have gone out, which in turn caused your fan motor and compressor to malfunction.

Do you see any bulges, oil spots, or dirt over oil near the capacitor?

134 days ago.

Reply

no the capacitor area is completely clear and clean

Posted by Kenton Guidry 134 days ago.

Answer

Your motor may be out, or the capacitor could be bad.

Your compressor is trying to start but cannot. Either the capacitor is bad, or the compressor has gone out.

Your contactor should not buzz that loud either. It is also possible that it is pitted and needs to be replaced as well.

The best case scenario is that your dual capacitor is out and a new one will fix your problem.

Worst case your fan motor is out, and your compressor is pulling too many amps.

134 days ago.

Reply

thanks for your help!

Posted by Kenton Guidry 134 days ago.

Info Request

You are very welcome.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

HVAC

Have your own HVAC question?

Question

i have a carrier air conditioner installed in august 2004. i can hear the power source getting to the unit, but it is not engaging the motor.

Info Request

Does the indoor fan work? What do you hear, and where do you hear it?

Reply

yes the indoor fan is working i have the panel off the outside unit and i can a humming or buzzing noise near what i think is a silonoid looking part. a silver sphere shape that has three electrical connections on top

Accepted Answer

Reply

i'm fairly sure the noise was from the capacitor, i will double check that. i know that the inside breaker is not tripped, i cant tell about the one on the outside i've never seen a breaker like it before.

Answer

Reply

the sound stopped after i turned the thermostat to off. i think the outside must be fuses, there is no breaker switch there.

Answer

Do you see fuses that look like the photo below? Your fuses will be larger than the photo example but will confirm that there are fuses. http://help.hudsoncarpentry.co.uk/Images/Electrics/howTo/changeFuse/fusesFig1.jpg The noise must be the contactor.

Reply

i dont see the actual fuses, just the box with a about 2/12 in square black front the has a small metal pull ring hanging in front

Answer

This must be a non fused disconnect. Can you turn your breaker to the condenser off, and then on. Then have someone turn on the air conditioner while you stand outside to watch and hear it. Let me know if it tries to start.

Reply

the noise is at the contactor and at times the motor will buzz like it wants to start but doesn't

Info Request

Go ahead and leave the power off. Does the fan located at the condenser ever come on?

Reply

a/c power is off. the fan on the outside unit(is that the condenser?) has not ever come on with or without power. the inside fan unit is still on now

Answer

That condenser fan (outside) should come on with your compressor. You will have to get a technician out. Your dual capacitor could have gone out, which in turn caused your fan motor and compressor to malfunction. Do you see any bulges, oil spots, or dirt over oil near the capacitor?

Reply

no the capacitor area is completely clear and clean

Answer

Reply

thanks for your help!

Info Request

You are very welcome.

Related HVAC Questions

i have a carrier air conditioner installed in august 2004. i can hear the power source getting to
the unit, but it is not engaging the motor.

Does the indoor fan work?

What do you hear, and where do you hear it?

yes the indoor fan is working

i have the panel off the outside unit and i can a humming or buzzing
noise near what i think is a silonoid looking part. a silver sphere shape that has three electrical connections on top

i'm fairly sure the noise was from the capacitor, i will double check that.
i know that the inside breaker is not tripped, i cant tell about the one on the outside i've never seen a breaker like it before.

the sound stopped after i turned the thermostat to off.
i think the outside must be fuses, there is no breaker switch there.

Do you see fuses that look like the photo below? Your fuses will be larger than the photo example but will confirm that there are fuses.

http://help.hudsoncarpentry.co.uk/Images/Electrics/howTo/changeFuse/fusesFig1.jpg

The noise must be the contactor.

This must be a non fused disconnect.

Can you turn your breaker to the condenser off, and then on.

Then have someone turn on the air conditioner while you stand outside to watch and hear it.

Let me know if it tries to start.

Go ahead and leave the power off.

Does the fan located at the condenser ever come on?

a/c power is off. the fan on the outside unit(is that the condenser?)
has not ever come on with or without power. the inside fan unit is still on now

That condenser fan (outside) should come on with your compressor.

You will have to get a technician out.

Your dual capacitor could have gone out, which in turn caused your fan motor and compressor to malfunction.

Do you see any bulges, oil spots, or dirt over oil near the capacitor?