Railway Equipment 934, Operating Manual

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P/N R9340-0104 7 © 2010 RAILWAY EQUIPMENT CO.
REV B
5/11
II. COMPONENT DESCRIPTION
A.
MAIN HOT AIR BLOWER (HAB) UNIT
1.
MAIN CIRCUIT BREAKER: Provides main over-current protection and
manual on-off control of electrical power.
2. MOTOR CONTACTOR: Provides automatic blower motor control, with high
current contacts.
3. MOTOR OVERLOAD RELAY: Protects the blower motor from an over-
current condition.
4. CONTROL MODULE: Provides complete control of operation. See separate
description and details, section IV.
5. AIRFLOW SWITCH: Located in the heat duct, the sail switch indicates proper
airflow before and during burner operation. The differential setting is determined
by elevation.
6. AIR TEMPERATURE SENSOR: This is an analog type sensing circuit to
monitor the ambient air temperature.
7. BLOWER MOTOR: The motor is totally enclosed and fan cooled.
8. BLOWER: The high efficiency blower wheel is dynamically balanced for
smooth and quiet operation.
9. BUZZER: The buzzer will sound a 10-second tone immediately before the
motor contactor is energized.