Heat pump and electrical baseboard, continuous or non-continuous load?

[katwalatapan]

Hello,

I wanted to inquire if while sizing a main electrical service panel feeder or a sub-panel feeder, would the heat pump electrical load and/or any electrical baseboard space heating load be considered as continuous or non-continuous load?

Also while sizing branch circuit conductors, would the same classification apply?

Thank you.

 

[cranky108]

The answer I always give, is it depends. In Florda the heating is non-continuous. In Alaska it is continuous. However, any air conditioning would not be operating at the same time as the heating (we would hope), except in special cases (like our substation buildings). Anything that can operate for hours on end should be consitered continuous, but should be evaluated like the example I gave for conditions.

 

[dpc]

Well, if you are sizing it now, I'd assume it was continuous. Per the NEC definition, continuous means three hours or more. I've always considered HVAC loads as continuous.

 

[PHovnanian]

Per the 2011 NEC (Sorry, I'm a bit out of date):

ARTICLE 424— FIXED ELECTRIC SPACE-HEATING EQUIPMENT
424.3(B) Branch-Circuit Sizing. Fixed electric space-heating equipment and motors shall be considered continuous load.

So its a continuous load for the purpose of branch circuit sizing. And using engineering judgment, I'd say continuous for feeders and service equipment as well unless you can demonstrate diversity between multiple heating loads and excess capacity based on worst case heat loss sizing.

 

[Sn00ze]

Unless it has a thermostat. Most heating units are continuous.