Duty Cycle; Maintenance; Fuse On Powered Type; Commerical Defrost Control - Carrier 50GCQ Series Service And Maintenance Instructions

UNIT CONNECT
VOLTAGE AS
208, 230 240
460 480
575 600
Fig. 29 — Powered Convenience Outlet Wiring

Duty Cycle

The unit-powered convenience outlet has a duty cycle limita-
tion. The transformer is intended to provide power on an inter-
mittent basis for service tools, lamps, etc; it is not intended to
provide 15A loading for continuous duty loads (such as electric
heaters for overnight use). Observe a 50% limit on circuit load-
ing above 8A (i.e., limit loads exceeding 8A to 30 minutes of
operation every hour).

Maintenance

Periodically test the GFCI receptacle by pressing the TEST button
on the face of the receptacle. This should cause the internal circuit
of the receptacle to trip and open the receptacle. Check for proper
grounding wires and power line phasing if the GFCI receptacle
does not trip as required. Press the RESET button to clear the
tripped condition.

Fuse on Powered Type

The factory fuse is a Bussmann
renewable screw-in (Edison base) type plug fuse.
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PRIMARY TRANSFORMER
CONNECTIONS TERMINALS
L1: RED +YEL H1 + H3
L2: BLU + GRA H2 + H4
L1: RED H1
Splice BLU + YEL H2 + H3
L2: GRA H4
L1: RED H1
L2: GRA H2
™1 Fusetron ™1 T-15, non-
USING UNIT-MOUNTED CONVENIENCE OUTLETS
Units with unit-mounted convenience outlet circuits will often re-
quire that 2 disconnects be opened to de-energize all power to the
unit. Treat all units as electrically energized until the convenience
outlet power is also checked and de-energization is confirmed.
Observe National Electrical Code Article 210, Branch Circuits, for
use of convenience outlets.

COMMERICAL DEFROST CONTROL

On 50GCQ units equipped with electro-mechanical controls or the
optional factory-installed RTU Open controller, the Defrost Con-
trol Board (DFB) coordinates thermostat demands for supply fan
control, 1 or 2 stage cooling, 2 stage heating, emergency heating
and defrost control with unit operating sequences. The DFB also
provides an indoor fan off delay feature (user selectable). See
Fig. 30 for board arrangement.
The DFB is located in the main control box of the 50GCQ unit
(see Fig. 31). All connections are factory-made through harnesses
to the UCB (unit control board), ECM (direct-drive motor),
reversing valve solenoids, and defrost thermostats. Refer to
Table 7 for details of DFB Inputs and Outputs.
NOTE: The Defrost Control Board is not used on units equipped
with the factory-installed SystemVu™ controller option.
Fig. 30 — Defrost Control Board Arrangement
20
DIP
Switches
Speed-Up
Jumpers