NEC 220.60 Noncoincidental Loads

Status
Not open for further replies.
HoosierSparky

HoosierSparky

Senior Plans Examiner, MEP
Location
Scottsdale AZ
Occupation
Senior Plans Examiner
What is a noncoincidental load as stated in NEC 220.60? This section just pops up with no definition. I went into the Handbook, which is NOT adopted by the jurisdiction and only used for direction and not CODE, and there is no help there either.
 
CONDUIT said:
A example would be heat and air conditioner not being used at same time.
Click to expand...

An HVAC unit and a tankless ELECTRIC water heater wouldn't be considered noncoincidental loads? I have MY opinion and it carries a lot of weight with ME, but.......................:angel:
 
HoosierSparky said:
An HVAC unit and a tankless ELECTRIC water heater wouldn't be considered noncoincidental loads? I have MY opinion and it carries a lot of weight with ME, but.......................:angel:
Click to expand...

The key takeaway to this definition is it is not just two loads that are unlikely to operate at the same time, but it is two loads that cannot operate at the same time by the nature of the switching and control.

So a heater and an air conditioner both controlled by the same thermostat would be non-coincidental, because the thermostat will only operate one mode at once. But a water heater and an HVAC system which have completely unrelated control systems, would not count. Even if the water heater operates a lot less often during the air conditioning mode.
 
Carultch said:
The key takeaway to this definition is it is not just two loads that are unlikely to operate at the same time, but it is two loads that cannot operate at the same time by the nature of the switching and control.

So a heater and an air conditioner both controlled by the same thermostat would be non-coincidental, because the thermostat will only operate one mode at once. But a water heater and an HVAC system which have completely unrelated control systems, would not count. Even if the water heater operates a lot less often during the air conditioning mode.
Click to expand...

Thank you! That is the direction I was going in my thought process.
 
Seekthetruth said:
Can you use the same circuit breaker as a feeder for a split AC system since they are noncoincidental?
Click to expand...

220.60 Noncoincident Loads
Where it is unlikely that two or more noncoincident loads will be in use simultaneously, it shall be permissible to use only the largest load(s) that will be used at one time for calculating the total load of a feeder or service.
Click to expand...

220.60 talks about feeder or service load calculations. If you had a feeder providing power to sub panel that supplies heating and also the A/C you would size the feeder according to the larger of the loads. The same would be true of the service calculations.

However, you are asking about supplying the A/C and heat from the same circuit. Unless both are included in a packaged unit, the A/C will require an MOP and MCA that may not be suitable for the heating. A/Cs are usually on dedicated circuits.

-Hal
 
CONDUIT said:
A example would be heat and air conditioner not being used at same time.
Click to expand...

I’m in the south, so I’m only familiar with what we use, which are packaged or split heat pumps. The compressor unit is typically used for heat & a/c, with emergency electric heat strips (usually 5kw or 10kw). Both of these can operate at the same time.


Sent from my iPhone using Tapatalk
 
Status
Not open for further replies.
Top