Control Transformer; Auxiliary Power Circuitry; Output Contactor Circuitry - Hobart GPU-600 Operation And Maintenance Manual

OM-2010
The main transformer of the 208/230/460-V power supply (Spec 6683-1 or 6883A-1) has a winding to
provide the 115-V AC for the auxiliary power receptacle and fan motor. The main transformer has a
center tapped coil on each phase that provides six sensing or synchronizing voltage signals to the
solid state printed circuit control board (13, Fig. 3).
The main transformer for the 220/380-V power supply (Spec 6683-2 or 6883A -2) has a 220-V AC
winding for its auxiliary power receptacle and a 110-V AC winding for the fan motor. Be certain to fol-
low the changeover diagram for both the main transformer and the control transformer (10, Fig. 3) for
the input voltage you have available.
CAUTION: IMPROPER CONNECTIONS WILL CAUSE DAMAGE. CONTACT FACTORY IF YOUR
EQUIPMENT SPECIFICATION INFORMATION AND/OR VOLTAGE CHANGEOVER DIAGRAM
DOES NOT AGREE WITH YOUR RATED 3 PHASE INPUT VOLTAGE.
C. Control Transformer (10, Fig. 3)
The small control transformer located on the rear of the inside baffle (3, Fig. 3) or lifting eye plate pro-
vides 115 V AC to the K1 (14, Fig. 3) input contactor coil, input contactor light A (12, Fig. 4), and S1
(11, Fig. 4) input contactor switch via the half amp F8 contactor fuse (20, Fig. 3) on the control trans-
former. This transformer does not provide the 9A, 115 V AC auxiliary power.
WARNING: ELECTRIC SHOCK CAN KILL! DISCONNECT INPUT POWER AT
SOURCE TO REMOVE VOLTAGE TO CONTROL TRANSFORMER AND INPUT
FUSES AND CONTACTOR.
D. Auxiliary Power Circuitry
The 115 V AC single phase auxiliary power receptacle (5, Fig. 4) has the same frequency as the pri-
mary input voltage. It is protected by the F1 fuse (9, Fig. 4) located on the power supply front panel,
typically, 15 Amperes. The auxiliary power circuitry is turned off whenever the primary contactor is
open or off. The auxiliary power winding is typically located on the middle leg (B phase) of the main
transformer. It provides power to the duplex 115 V AC receptacle (5, Fig. 4) and to the fan motor.
A "MOV" voltage surge suppressor, RV (6, Fig. 4), is installed across the 115 V AC receptacle termi-
nals to reduce voltage surge problems to the load equipment and the power source.
E. Output Contactor Circuitry
Output contactor K2 (9, Fig. 3) is operated by the output contactor ON-OFF switch S2 (11, Fig. 4).
Placing this switch momentarily in the UP (spring-loaded) position turns the output contactor ON, and
placing it in the DOWN position turns the output contactor OFF.
The positive output lead is to be connected to the positive output terminal of the K2 contactor. The
negative output lead is to be connected to the negative bus bar (5, Fig. 3) of the C15-C17 output filter
capacitor bank (4, Fig. 3) . A small notch has been made in the bottom of the right and left side panels
to allow for the output cable assembly to pass out either side.
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April 10/89 Revised