Cold Weather Starting System - Hobart 60CU24 Operation And Maintenance Manual With Illustrated Parts List

OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set
(1) Line-Drop Compensation
The current transformers detects the magnitude and power factor of current flowing from
generator to load. They feed a signal to the voltage regulator that interprets the signal and alters
the exciter field current as required to maintain a constant predetermined voltage at the load.
(2) Ammeter
The current transformers convert a current signal to a voltage signal, which is sent to the Voltage
Regulator PC Board (REG). The ammeter is really a voltmeter graduated and numbered in
amperes to show current proportional to the voltage signal received.
When there is overload on the output for more than 5 minutes (load exceeding 326 amperes per
output or 125% of rated load), the main overload sensing circuit sends signals the load the
contactor(s) circuit to open both load contactors.
(3) Overload, No 1 and/or No. 2 output (if applicable)
On each individual output the current transformers converts a current signal to a voltage signal.
The voltage signal is sent to the ammeter and to the overload monitoring circuit for that output.
The overload monitoring circuit will open the contactors when the output current reaches 125% of
the normal rated output current. The monitoring circuit moniters each individual output, as well
as, the overall current for a dual output machines.
The following is a list of overload module characteristics:
•
At 125% load the module will function in 5 minutes.
•
At 150% load the module will function in 30 seconds.
•
AT 200% load the module will function in 10 seconds.
NOTE: The overload protective system will function when any phase carries 123% to 127% of
rated load. All times are plus or minus 25% and are non-adjustable.

9) Cold Weather Starting System

CAUTION
Drain the engine coolant system before working on the block heater. Afterwards, refill
the cooling system and bleed at highest point to remove any air locks.
The block heater kit is installed inside the enclosure of the engine/generator set, and is connected to the
cooling system of the diesel engine. Its purpose is to keep the coolant warm when the engine is shut
down for extended periods of time in cold weather, and thus permit the engine to start more quickly.
The block heater unit is mounted to the engine/generator frame with a bracket and attaching hardware.
Hoses, clamps, and fittings connect the block heater to the engine's cooling system.
Mounted low in the system, a head pressure is maintained at the heater's intake and a simple one-way
valve in the heater unit ensures the direction of coolant flow.
November 16, 2007
Revision 8
Chapter 1-1
Page 22