Transformer-Rectifier Operation; Direct Current Power Delivery; Simultaneous 28.5-V Dc And 115-V Ac Power Delivery - Hobart 90 C 20 Operation And Maintenance Manual

OM-2031
4. Transformer-Rectifier Operation (Optional Equipment) (See Fig. 5)
Transformer-Rectifier operating instructions are contained in its operating manual, however some gener-
ator set instructions are required here.
A. Direct Current Power Delivery
NOTE: If the customer adds a Transformer-Rectifier to a standard machine which was NOT equipped
with a T-R when it left the factory, he must remove the jumper lead which will be found on the small
terminal strip in the generator set voltage regulator (see 1-1; 19, Fig. 12). If your generator set has a
factory installed T-R, the jumper will have been removed.
(1) When delivering power from a T-R, prepare the generator set for DC power delivery the same as
for AC delivery, except do not connect AC output cable and do not close AC load contactor (see Para.
2, D and E).
(2) For T-R operating instructions, see Hobart Manual No. OM-433.
B. Simultaneous 28.5-V DC and 115-V AC Power Delivery
If both 28.5-V DC and 115-V AC must be delivered at the same time, the following rules and precau-
tions must be observed.
(1) Place T-R current limiting switch in OFF position. This will eliminate the soft start feature of the T-
R, but will prevent AC voltage from dropping low enough to trip the AC load contactor.
(2) Line-drop compensation on the T-R must be REDUCED or turned DOWN completely to prevent
opening of the AC load contactor by an overvoltage condition. Readjust T-R line-drop compensation
so that AC voltage (as indicated by the generator set voltmeter) does not exceed 118-V AC when the
DC load is 500 Amperes. If higher DC voltage is needed, adjust T-R line-drop compensation as re-
quired.Observe AC voltage while making this adjustment to be certain that it does not go TOO HIGH
with DC load.
(3) During simultaneous, continuous operation, loads on either circuit are limited only by the capaci-
ties of their respective circuits, however, the combined loads should not exceed the rated capacity of
the generator set (90 KVA or 72KW).
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Test Receptacle
Connector
Figure 4
October 1/95 Revised