4
HEATER LOAD CONNECTION
• Provide 3-phase contactors C1 and C2 with up to 600 VAC,
50 AMP maximum per pole.
• Provide contactor C5 with up to 277 VAC, 30 AMP.
• Make sure the wire Gauge (AWG) is suitable for the circuit
amperage draw, as specified in the NEC/ CEC table 1.
MAIN SUPPLY FOR THE POWER BOX
• Provide terminals L1, N1 with 120 V supply.
CONNECTION TO THIRD-PARTY ICE/SNOW
SENSOR (GIT-1 / CIT-1 / SIT/6E) - OPTIONAL
• 3-wire shielded cable
• Up to 2,000 ft (609 m) using 12 AWG 3-wire shielded cable.
• Up to 500 ft (152 m) using 18 AWG 3-wire shielded cable.
CONNECTION TO SNOW SENSOR
(PYROSENSE)
Please refer to the PYROSENSE installation section of this
manual.
2
1
A
C C R
C
B
R
L1 N1
R
F-5A
R
IN
IN
1
2
A1
A
C1
B1
B
C
A1
A
C1
B1
B
C
IMPORTANT ! If the heaters are connected in a star configuration, the neutral must pass through the internal current
transformer ring and the external branch circuit protection.
CAUTION: Incorrect voltage may cause fire or seriously damage the unit.
60 A, 600 V max.
30 A, 277 V max.
GFCI
GFCI
Transformer
130 VA
120/24 V
C.T. (Current transformer)
Black
Black
Red
Red
White
Blue
White
Internal connections
See
Appendix 1
Heater load connection
L1, L2, L3 – 600 V max.
50 A max. per pole
Heater load
connection
277 V, 30 A
max.
Main
supply
120 V
Third-party
ice/snow
sensor
(optional)
PYROULS
Upper limit
temp. sensor
(by STELPRO)
PYROSENSE
Snow sensor
(by STELPRO)
Inter
nal connections
Branch circuit protection
and disconnect provided
by installer
Shield wire
PYROBOX3C
