Electric Air Handler - Heat Pumps

[Scott Schultz]

When I come across a heat pump air handler, the label on it is never marked as to which heating element is installed, thus not able to correctly identify if the associated breaker is of the correct amperage and not overamped. Are there other ways to determine this?

[Charley L. Bottger]

Originally Posted by Scott Schultz

When I come across a heat pump air handler, the label on it is never marked as to which heating element is installed, thus not able to correctly identify if the associated breaker is of the correct amperage and not overamped. Are there other ways to determine this?

In reading your post I think you do not have a understanding in the operational theory of a heat pump. Your statement (Which heating element) is my clue.

A heat pumps primary source of heat is the reverse cycle of the freon and will just require the outside condensing unit and the indoor blower fan section to be operating. If an electrical furnace is used as the secondary source of heat the name plate data will normally tell the KW of the electrical heat strips and its breaker would be rated for the amount of strips installed within the furnace. That probally is as clear as MUD.

[away]

Charley,
Dang I hate to admit that Oklahoma may be more advanced than Texas, well at least just this once , but I see this quite often. The date tag will have a list of heater strips that may be installed but no marking whatsoever as to which one is actually there. I have seen this on heat pump systems with secondary heat strips, traditional electric heating, new homes, old homes, whatever.

[Scott Schultz]

I know how heat pumps work, but my question is how do you tell if the aux. heat strips are installed in that particular unit and if so, which one which depending if they are or not, would dictate the max. amps of the circuit breaker.

[Scott Schultz]

Andrew,

Exactly.

[bbenjamin]

Originally Posted by Scott Schultz

I know how heat pumps work, but my question is how do you tell if the aux. heat strips are installed in that particular unit and if so, which one which depending if they are or not, would dictate the max. amps of the circuit breaker.

Their is no quick way to tell if heat strips are installed or what kilo wattage they are. The only way to be certain is to open the unit and verify it yourself which should only be done by a qualified h.v.a.c professional as it is beyond the scope of the s.o.p of home inspections.

[Charley L. Bottger]

Originally Posted by Scott Schultz

I know how heat pumps work, but my question is how do you tell if the aux. heat strips are installed in that particular unit and if so, which one which depending if they are or not, would dictate the max. amps of the circuit breaker.

Scott it is very hard to tell someones knowledge level on this board; some questions are hard to understand. I wasn't trying to degrade you.

Lets start this over
You can not tell how many strips are in a furnace by looking at the name plate this is a correct statement. You have to remove the front cover and actually observe the amount of strips present. I have stated this many times and other HVAC guys disagree that an HI should do this but I use a amp meter on the individual strips to determine if they are working or not.

These furnaces use a sequencer switch to time the strips on so they do not all come on at the same time. The breaker size is going to be determined by the amount of strips in use for the particular furnace. Just looking at the breaker size will tell you nothing. So basically there is no hard fast rule to go by

If I observed a 30 amp or a 40 amp double pole breaker on a furnace I am going to see how many strips are in use. Most furnaces that I see normally have at least a 60 amp breaker in use. If you have two strips pulling 25 amps per strip common sense should dictate the size. Again this can only be determined with an amp meter. Other than that you are just shooting in the dark.

[Scott Schultz]

Understood. Thanks for the info. It would be nice if the installers of these units would take an extra 2 seconds and check off which element is installed so we can make sure the unit is not overamped at the breaker.

[David A. Andersen]

Their is no quick way to tell if heat strips are installed or what kilo wattage they are.

Turn on the emergency heat switch. Turn the thermostat all the way up. With the cover removed from the disconnect, take the amperage reading. Use owns law to convert the amperage to wattage (W = V x A) and you will see how many K. W. the heater is.

That was quick!

Another quickie...

Take the cover off the air handler and look inside.
Most heat banks are labeled and you can count them.

[Charley L. Bottger]

Originally Posted by dandersen

Turn on the emergency heat switch. Turn the thermostat all the way up. With the cover removed from the disconnect, take the amperage reading. Use owns law to convert the amperage to wattage (W = V x A) and you will see how many K. W. the heater is.

That was quick!

Another quickie...

Take the cover off the air handler and look inside.
Most heat banks are labeled and you can count them.

I like Quickies
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