HVAC Electrical Specifications
HVAC Electrical Specifications
(OP)
Hi, may be I'm missing something. Sometimes when I asked for the electrical specifications/requirements on an HVAC unit condensing/AHU, the people give me the tons. Like 4 tons 15 tons. Is there any way that you can size the min/max protection on these units just having the capacity in tons?. If no what may be the reason on refering to the capacity in tons when all I need is to protect the motor/compressor?. Just in case I'm not interested on converting tons to watts or BTU.
Thank you.
Thank you.





RE: HVAC Electrical Specifications
Ed
www.engineerboards.com
RE: HVAC Electrical Specifications
RE: HVAC Electrical Specifications
I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int./JCI
RE: HVAC Electrical Specifications
RE: HVAC Electrical Specifications
RE: HVAC Electrical Specifications
RE: HVAC Electrical Specifications
RE: HVAC Electrical Specifications
RE: HVAC Electrical Specifications
i.e. no. of each equipment and the rating of each.
Insist on this.
For bigger equipments, there may be 2 power inputs for a single chiller, in some instances.
HVAC68
RE: HVAC Electrical Specifications
The list includes everthing electrical types should need to know to size wires, starters and protection.
RE: HVAC Electrical Specifications
Gee, I think I just got a promotion! :>)
RE: HVAC Electrical Specifications
RE: HVAC Electrical Specifications
Thank you all for your help.
RE: HVAC Electrical Specifications
An HVAC unit may have multiple components including but not limited to compressors, fans, heaters, controls, etc. Starting current (which is close to locked rotor amps(LRA)) of unit components may be 5 times component RLA so take a look at voltage drop under starting conditions. If feeders are sized only for MCA then starting voltage drop can be so bad that a compressor will stall. Reciprocating compressors have an especially high initial amp draw.
Generally heating components will not operate at the same time as cooling, but this is not always true. Demand the catalog electrical cutsheets and a wiring diagram that shows the field wiring. The manufacturer may supply a disconnect, but it may arrive lying in a box and require installation.
After all is said remember that competive bidding allows substitutions that will give you a different manufacturer and of course varying ampacities, that is why the electrical guys get the big money.