UH-60 IPC/MOI 02-006 CW2 JAMES THOMAS

ELECTRICAL SYSTEM FIRE DETECTION AND EXTINGUISHING SYSTEMS UH-60 ELECTRICAL SYSTEM FIRE DETECTION AND EXTINGUISHING SYSTEMS

REFERENCES OPERATOR’S MANUAL FLIGHT LINE SUPPLEMENT STUDENT HANDOUT

ELECTRICAL SYSTEM OVERVIEW AC SYSTEM AND COMPONENTS DC SYSTEMS AND COMPONENTS EP’s

Alternating Current is the primary source of power.

The primary electrical system consists of two independent systems, each of which is capable of supplying the total helicopter power requirements.

COMPONENTS OF AC SYSTEM TWO MAIN GENERATORS ONE AUXILIARY GENERATOR ONE EXTERNAL RECEPTACLE THREE GENERATOR CONTROL UNITS ONE EXTERNAL POWER MONITOR TWO AC PRIMARY BUSES ONE AC ESSENTIAL BUS SIX CURRRENT LIMITERS

GENERATORS The two main generators are identical and interchangeable. They are located on the right and left hand transmission accessory gearboxes.

The main generators are: three phase, 115/200 volt ac, 400 Hz, OIL COOLED generators.

APU GENERATOR The auxiliary generator is located on the auxiliary power unit.

The auxiliary or APU generator is a three phase, 115 volt ac, 400 Hz, AIR COOLED generator. It provides AC power for ground operations and for in-flight emergencies.

Each generator is capable of assuming another generators load in case of a failure.

This system works in priority; The main generators have priority over the APU generator and the APU generator has priority over external power.

GENERATOR CONTROL UNIT A GCU controls voltage output and provides circuit protection.

There are three Generator Control Units in this system: one for each generator.

FUNCTIONS OF THE GCU Voltage Regulation Under Voltage Protection Over Voltage protection Under Frequency Protection Feeder Fault

AC BUSES #1 AC primary bus is powered by the #1 main generator. AC essential bus is normally powered by the #1 primary bus.

CURRENT LIMITERS Six Current Limiters Three for each Primary Bus 60 Amp Works like a fuse - excessive amps melt metal and open circuit that goes across the current limiter

EXTERNAL POWER External Power Receptacle Third Priority External Power Monitor

EXTERNAL POWER MONITOR Under Voltage Protection Over voltage protection Under frequency Protection Over frequency Protection Correct Phase Rotation

DIRECT CURRENT SYSTEM

DC SYSTEM COMPONENTS BATTERY CHARGER/ANALYZER TWO DC PRIMARY BUSES ONE DC ESSENTIAL BUS TWO AC/DC CONVERTERS CURRENT LIMITER

CONVERTERS Two 200 amp air cooled converters Input voltage… 3 phase,115 volt ac, 400 Hz Output voltage… 28 volts dc

DC BUSSES 2 DC PRIMARY BUSSES 1 DC ESSENTIAL BUS 1 BATTERY UTILITY BUS 1 BATTERY BUS

When battery is sole source of DC power…. DC BUSSES When battery is sole source of DC power….

Battery Utility Bus is hot when battery is connected. Battery Bus is hot when battery is connected and battery switch is on. DC Essential Bus is hot when battery is connected, switch is on and 35% charge.

CURRENT LIMITER One 100 amp current limiter Provides protection to circuits in the event of excessive amperage or draw.

The battery is 24 volts dc, 5.5 amp hours, with 20 cells. (Nicad only)

The battery is the secondary or emergency source of DC power.

When the battery is the sole source of DC power, it is limited to 22 minutes of day operation and 14 minutes of night operation at 80% capacity.

CHARGER ANALYZER Provides a constant charge to the battery when the #2 AC primary and #2 DC primary busses are energized. Analyzes the battery, controls Battery Low and Fault Caution Lights, and disengages the DC essential bus when battery capacity drops below 35%.

WHICH LIGHTS ILLUMINATE WHEN THE BATTERY SWITCH IS PLACED ON?

#1 CONV AND #2 CONV AC ESS BUS OFF BOOST SERVO OFF STABILATOR SAS OFF

WHEN DOES THE BATT LOW CAUTION LIGHT ILLUMINATE?

THE BATT LOW CAUTION LIGHT ILLUMINATES WHEN THE BATTERY STATE OF CHARGE IS AT OR BELOW 40% CAPACITY.

EMERGENCY PROCEDURES

MASTER CAUTION #1 GEN

9.26.2 #1 OR #2 GEN Caution Light On 1. Affected GENERTORS switch RESET; then ON if caution light remains on: Affected GENERATORS switch OFF

MASTER CAUTION #1 CONV #2 CONV AC ESS BUS OFF STABILATOR

9.26.1 #1 and #2 Generator failure SAS 1 switch - press off. Airspeed - Adjust ( 80 KIAS or less ) GENERATORS NO. 1 and NO. 2 switches - RESET; then ON. If caution lights remain on: GENERATORS NO. 1 and NO. 2 SWITCHES - OFF. EMER APU START SAS 1 switch - ON LAND AS SOON AS PRACTICABLE.

FIRE DETECTION AND EXTINGUISHING SYSTEMS

OVERVIEW DEFINITIONS COMPONENTS OPERATION EP’s WARNINGS

FIRE DETECTION SYSTEM The fire detection system provides fire warning to the cockpit in case of fire in either main engine or APU compartments.

The system consists of the following components. 5 Radiation Sensing Flame Detectors 3 Control Amplifiers 3 Arming Levers Fire Detector Test Panel

FIRE EXTINGUISHING SYSTEM A high-rate discharge extinguishing system provides a two shot, main and reserve capability to either main engine compartment or APU compartment.

The Fire Extinguishing system consists of the following components 3 Fire Extinguishing Arming Levers Fire Extinguisher Control Panel High Rate Discharge System Omni-directional inertial switch

System Sequence Fire Master Caution and Warning light T-Handle Pull Aft Fire Extinguisher Switch High-Rate Discharge

9.23.4 Engine Fire in Flight. ENG POWER CONT lever ( affected engine ) - OFF. ENG EMER OFF handle - pull. FIRE EXTGH switch - MAIN/RESERVE as required. LAND AS SOON AS POSSIBLE.

WARNING If AC electrical power is not available, only the reserve fire bottle can be discharged and fire extinguishing capability for the #2 engine will be lost.

REVIEW DEFINITIONS COMPONENTS OPERATION EP’s WARNINGS