User manual

Chapter 2: Installing your SEC-HD Phason
16
Using three-phase power
If you are connecting your SEC-HD to a three-phase system, connect the control power and the
variable cooling equipment to the same phase.
Your SEC-HD must be powered from the same phases that supply the equipment. If your SEC-HD
power and the variable stages are wired to different phases, the equipment will operate erratically.
Connect the control power and variable cooling equipment as shown in the following example.
Correct three-phase wiring Incorrect three-phase wiring
Connecting single-stage heating or cooling elements
Heating or cooling elements include electric heaters, furnaces, and single-speed fans.
The ratings of the equipment must not exceed the ratings of your SEC-HD's relays.
Relay ratings: 6 A at 120/230 VAC, general-purpose (resistive)
1/3 HP at 120 VAC, 1/2 HP at 230 VAC
360 W tungsten at 120 VAC
Relay fuses: 12 A, 250 VAC ABC-type ceramic
Gas furnaces using hot-surface ignition or glow plugs can draw more current than
indicated on their nameplate and require power contactors. For more information,
read your furnace dealer.