Three Phase Power Supply Connection (Sc-3000 & Sc-4000 Only) - Harsco Industrial SC-1500 Owner's Manual

3.2.3 Three Phase Power Supply Connection (SC-3000 & SC-4000 Only)
Main Power Connection Box
Check the rating nameplate of the SC-3000 or SC-4000 boiler to determine the required electrical service:
208-240VAC, three phase, 60 hertz
•
440-480VAC, three phase, 60 hertz
•
The incoming three phase power for the SC-3000 & SC-4000 boilers is connected to the over-current safety
device (rated for 20 Amps) and the Ground terminal located in the main power connection box. The
illustration below shows the Low Voltage (TB1) and High Voltage (TB2) terminal blocks, plus the Main Power
Connection Box on the SC-3000 & SC-4000 with the front door hidden for clarity:
Terminal 1 = HOT L1
•
Terminal 3 = HOT L2
•
Terminal 5 = HOT L3
•
Terminal G = GROUND
•
The Main Power Connection Box features a Control Transformer which steps down two hot leads from
the incoming three-phase power in order to supply 110-120VAC single phase power to the boiler's control
system. Be aware that SC-3000 & SC-4000 boilers ordered in the 240V configuration, are pre-wired from the
factory for operation with 240 VAC three phase incoming power.
If 208 VAC three phase power is supplied to the boiler, the internal control transformer must be re-wired for
operation at this lower voltage. The wire in terminal X3 on the load side of the internal control transformer
must be moved to terminal X4. This supplies the 120 VAC power to the controls from the 208 VAC main
voltage. Refer to Section 6.1
Do not over-tighten the hot lead
terminal screws. Maximum tightening
torque = 13 in-lbs!
NOTE
The hot lead terminals can
accommodate maximum 12AWG wire.
The ground terminal can
accommodate maximum 8 AWG wire.
for proper wiring and configuration of
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the internal control transformer.