I'm installing a new air handler (Goodman MBR 2000) in my home. I ordered a 15 kw heat strip kit (HKA-15C) to put in it. The kit has 2 breakers inside the air handler. (a 50 amp and a 25 amp) Instead of running 2 circuits with a #6 for the 50amp and a #10 for the 25amp they make a terminal block (SPW-01) to just run one circuit from the breaker panel to the air handler. I'm not sure if this just a terminal block, a power distribution terminal, or what so I'm trying to find out if I will need to run a larger wire than a #6 from panel to handler. a Guy from Hacy HVAC Supply has told me that all I need is the#6 and a 60amp in the breaker box. That the sequencers will rotate the heat strips where it won't ever pull more than 50amps. It seems like if I am using 15kw all three strips will be on together? I need to find out exactly what size wire and breaker I need to install the SPW-01 to keep me from running 2 lines. I don't want to run a #6 and find out it's not big enough. Would you please help me?

What do the installation instructions say? This information is required to be there by law...

The installation instructions don't say anything about the wiring from the unit to the breaker panel

Why do you say you need #6 AWG conductors?

If that information is contained in the instructions, then certainly the OCPD, type of conductor and the temperature of the terminals should be give. It is required.

For example a THHN (type) - 6 AWG (size) - 75(C) (terminal connection temp) can be used for up to 65 amps.

From what I have read on the Goodman Manf. Site, it appears to me that the "Heat Strip" circuitry is managed by the internals of the air handler. In effect, one supply circuit is required to the unit from the panelboard.

The installation of the heat strip does not require further changes to the electrical supply to the unit.

The installation instructions don't say anything about the wiring from the unit to the breaker panel

Are you sure? The installation instruction will typically list the "MCA" or minimum circuit ampacity... and also the "MOCP" or maximum overcurrent protection.

When you find the above, then you can correctly size the wire and fuse or circuit breaker.

I sent a note to Goodman. According to Goodman, a second 30 amp circuit is required for the heat strips.

I strongly suggest that you contact an trained HVAC technician for additional information.