York 10 ton heat pump with 2 stage electrical heat fed from two sources

[Dbronx]

the 113 amp rated Central ac/heating unit. The 3 phase heat pump draws 60 amp the 3 phase 18kw heating element draws 62.5 amps. allow There are 200 The highest amprage circuit breaker in QO panels 100 amps. The Central ac/heating unit draws 113 amps, so I would like to use two electrical sources 60 amps one panel for heat pump & 70 from another panel for heating element.
Has anyone done this and is it NEC compliant?

 

[augie47]

You will need to make sure you have supplemental protection on your heat (424.22)

 

[ActionDave]

the 113 amp rated Central ac/heating unit. The 3 phase heat pump draws 60 amp the 3 phase 18kw heating element draws 62.5 amps. allow There are 200 The highest amprage circuit breaker in QO panels 100 amps. The Central ac/heating unit draws 113 amps, so I would like to use two electrical sources 60 amps one panel for heat pump & 70 from another panel for heating element. Has anyone done this and is it NEC compliant?

Couple of thoughts -

I'm pretty sure you can get a 125A QO breaker.

Do the heat and cooling require individual feeds? In my experience they don't since the heat and cooling don't run at the same time.

 

[texie]

the 113 amp rated Central ac/heating unit. The 3 phase heat pump draws 60 amp the 3 phase 18kw heating element draws 62.5 amps. allow There are 200 The highest amprage circuit breaker in QO panels 100 amps. The Central ac/heating unit draws 113 amps, so I would like to use two electrical sources 60 amps one panel for heat pump & 70 from another panel for heating element.
Has anyone done this and is it NEC compliant?

Assuming that the 113 amp figure you mention is the MCA from the nameplate would lead be to think that this is a package unit with a single set of power input terminals and the loads are sub divided internally by the manufacturer. That would indicate a single branch circuit is required as there would be no compliant way to split it up. Or maybe I'm not understanding correctly?

 

[jxofaltrds]

424.19
*****Where heating equipment is supplied by more
than one source, the disconnecting means shall be grouped
and marked.******

This what you're looking for?

 

[kwired]

the 113 amp rated Central ac/heating unit. The 3 phase heat pump draws 60 amp the 3 phase 18kw heating element draws 62.5 amps. allow There are 200 The highest amprage circuit breaker in QO panels 100 amps. The Central ac/heating unit draws 113 amps, so I would like to use two electrical sources 60 amps one panel for heat pump & 70 from another panel for heating element.
Has anyone done this and is it NEC compliant?

Actual nameplate data will help us understand exactly what you have. If unit is designed for a single supply then you are likely stuck with installing a single supply.

Couple of thoughts -

I'm pretty sure you can get a 125A QO breaker.

Do the heat and cooling require individual feeds? In my experience they don't since the heat and cooling don't run at the same time.

QO plug on series breakers only go up to 100 amps. QOB series does go to 125 amps, and even up to 150 amps in some of the higher rated interrupting devices - but you must have a panel that accepts bolt on breakers to use them.

 

[Dbronx]

If a 125 QO breaker is avalible what is the square D unit requires 113 amps for both heat pump & heating coil, it is a 2 stage heating system. The heat pump will start heating, if it it is too cold the heating coils will energise, and they will both run at the same time . part discribtion

Couple of thoughts -

I'm pretty sure you can get a 125A QO breaker.

Do the heat and cooling require individual feeds? In my experience they don't since the heat and cooling don't run at the same time.

 

[augie47]

As best I can tell, in a 3 phase breaker, QO series, 100 amp is the largest.
IMO, you can install the circuits from different panels as long as you have disconnects grouped and marked (424.19) and your heating elements are protected by an over-current device not exceeding 60 amps (424.22) (that over-current device can be supplemental)

 

[kwired]

If a 125 QO breaker is avalible what is the square D unit requires 113 amps for both heat pump & heating coil, it is a 2 stage heating system. The heat pump will start heating, if it it is too cold the heating coils will energise, and they will both run at the same time . part discribtion

Let me tell you a little secret the NEC does not take in consideration - if it is too cold for heat pump to keep up with demand, the current drawn by heat pump is well below nameplate rating, like as low as 20% of that rating. That said there is a good chance that a 100 amp breaker would never trip, but I didn't tell you to violate codes:happyno:

Is the unit designed for single feed or for multiple feeds? Some are convertible.

 

[John120/240]

enlighten me

enlighten me

the 113 amp rated Central ac/heating unit. The 3 phase heat pump draws 60 amp the 3 phase 18kw heating element draws 62.5 amps. allow There are 200 The highest amprage circuit breaker in QO panels 100 amps. The Central ac/heating unit draws 113 amps, so I would like to use two electrical sources 60 amps one panel for heat pump & 70 from another panel for heating element.
Has anyone done this and is it NEC compliant?

I'm confused It sounds like two seperate services with two seperate meters X 200 units ?

The outdoor heat pump & E heat should never be on at the same time ? correct

What is wrong with the old fashioned way ? Panel sized to carry the load. Run wire from

panel to air handler. Run wire from panel to condenseor. Done. I'm in the dark here.:?

 

[kwired]

I'm confused It sounds like two seperate services with two seperate meters X 200 units ?

The outdoor heat pump & E heat should never be on at the same time ? correct

What is wrong with the old fashioned way ? Panel sized to carry the load. Run wire from

panel to air handler. Run wire from panel to condenseor. Done. I'm in the dark here.:?

It is not real clear as OP worded it. I took it as being a 200 amp panel, but there are other panels available to feed from, never considered multi-meter circumstances?

Whether or not heat pump and E heat run at same time depends entirely on the controls. Some instances where you turn the thermostat up more than a couple degrees or so will call for both heat pump and E heat for faster recovery to achieve set point. Defrost mode usually runs heat pump in cooling mode to bring heat to outdoor coil for defrosting it, and they also turn on E heat sometimes during defrost cycle.

I think he is trying to do this the old fashion way, but problem is he needs a 125 amp breaker and they don't make one for the particular panel he has, therefore he is inquiring about dividing the load into multiple smaller circuits.