Generator Set Adjustment; Generator Adjustment; Generator Control Adjustments - Hobart 140GT17P Operation And Maintenance Manual With Illustrated Parts List

OM-2029

3. Generator Set Adjustment

A. Generator Adjustment
The 400-Hz generator is a brushless type requiring no adjustments of any kind.
B. Generator Control Adjustments
The following items may require adjustment at some time during the life of the equipment.
(1) 400-Hz Voltage Regulator
To adjust 400-Hz voltage regulator, refer to TM-759 or OM-2020 for your particular regulator.
(2) Generator Overload Relay Ballast Resistor
For identification of the generator overload relay ballast resistor, refer to Schematic-Connection
Diagram No. 280170, sheets 1 and 5, in Chapter 6, This resistor is identified as R1 on these
sheets, and - as sheet 1 (the schematic) shows - this resistor is in the exciter field circuit. The ad-
justment of this variable resistor determines the trip point of the overload relay, which is identified
as K3 on sheet 1 of Diagram 280170.
Both of these items are shown in Figure 8, Sheet 1 of Section 1-1: the generator overload resistor
as item 24, and the overload relay as item 19. As Figure 2A shows, the resistor has a slider band
which fastens on the body of the resistor with a clamping screw
To adjust the overload ballast resistor, proceed as follows:
(a) Loosen slider-band clamping screw.
(b) If a proper load bank is available, apply full-rated load (140-KVA) to the generator set and po-
sition the slider on the resistor to produce 4.5 V-DC across the overload relay heater element. If
no proper load bank is available, adjust the resistor for 2.25 V-DC across the overload relay
heater element at no load.
(c) Tighten slider-band clamping screw when adjustment is completed.
2-3
Page 8
Generator Overload Relay Ballast
Resistor
Figure 2A
September 30/89 Revised