General
The ground service bus supplies 115v ac power to the water drain line heater circuits. There is one circuit breaker for the forward drain line heaters and one circuit breaker for the aft drain line heaters. The forward drain lines connect to the forward drain mast and the aft drain lines connect to the aft drain mast.
Functional Description
A thermostat (bi-metallic switch) opens the heater circuit when the temperature at the thermostat is 60F (16C) or more. When the temperature is 45F (7C) or less, the thermostat closes the heater circuit. In most circuits, the thermostat controls power to more than one heater.
An overheat switch in the heater opens if the temperature is 243F (117C) or more. The overheat switch does not reset. Most circuits have several heaters in series. If an overheat switch opens, it removes power from all the heaters in the series circuit.
EFFECTIVITY BEJ ALL  30-71-00 
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DRAIN AND WATER SUPPLY LINE HEATING -WATER DRAIN LINE HEATERS -FUNCTIONAL DESCRIPTION

EFFECTIVITY BEJ ALL  30-71-00 
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D633W101-BEJ  Jan 05/2002 

DRAIN AND WATER SUPPLY LINE HEATING -WASTE TANK RINSE FITTING HEATERS

General
There are three waste tank rinse fittings. The rinse fittings connect the waste tank rinse lines to the waste drain service panel. Each rinse fitting has a heater boot identified as the waste tank rinse fitting heater. The rinse fitting heaters are interchangeable LRUs.
The waste tank rinse fitting heater has a power wire and a ground wire. The power wire does not have an electrical connector. You need to splice the power wire when you replace a rinse fitting heater.
The waste tank rinse fitting heater has an integral thermostat and an integral overheat thermostat.
Location
The waste tank rinse fitting heaters are below the bulk cargo compartment floor. You can access the heaters through an access panel on the floor of the bulk cargo compartment.
Functional Description
The integral thermostat controls the power for the waste tank rinse fitting heater. The thermostat closes the circuit as temperature decreases below the freeze temperature. The thermostat opens the circuit to prevent too much heat.
The integral overheat thermostat prevents damage to the heater if the integral thermostat fails.
The integral thermostat opens the circuit when the temperature is greater than 80F (26C). The circuit closes when the temperature is less than 45F (7C). The integral overheat switch opens the circuit when the temperature is greater than 110F (47C). The circuit closes when the temperature is less than 80F (26C).
EFFECTIVITY BEJ ALL  30-71-00 
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DRAIN AND WATER SUPPLY LINE HEATING -WASTE TANK RINSE FITTING HEATERS

EFFECTIVITY BEJ ALL  30-71-00 
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D633W101-BEJ  Jan 05/2002 

DRAIN AND WATER SUPPLY LINE HEATING -WASTE TANK DRAIN LINE HEATERS -INTRODUCTION

General
There are three waste tank drain lines. Each drain line has a valve. The lines and valves all have thermostatically-controlled heater blankets.
Each heater blanket has an integral thermostat and a overheat switch that can not be reset. Each heater is an LRU. Drain line blankets are not interchangeable. Valve blankets are interchangeable. Drain line blankets are not interchangeable with valve blankets.
The heater blankets have electrical connectors.
Location
The heater blankets are below the waste tanks. You can get access to them through the same panels that supply access to the waste tanks.
EFFECTIVITY BEJ ALL  30-71-00 
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DRAIN AND WATER SUPPLY LINE HEATING -WASTE TANK DRAIN LINE HEATERS -INTRODUCTION

EFFECTIVITY BEJ ALL  30-71-00 
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DRAIN AND WATER SUPPLY LINE HEATING -WASTE TANK DRAIN LINE HEATERS -FUNC. DESC.

General
The heater blankets on the waste tank drain lines operate the same as the heater blankets on the drain valves.
Functional Description
Each heater blanket has an integral thermostat and an overheat switch. The thermostat supplies electrical continuity as temperature decreases below freezing. As temperature increases, the thermostat opens the circuit to prevent too much heat. The thermostat opens the circuit when the temperature is greater than 80F (26C). The thermostat closes the circuit when the temperature is less than 45F (7C). The overheat switch opens the circuit when the temperature is greater than 243F (117C). If the overheat switch opens the circuit, the circuit will not automatically reset.
EFFECTIVITY BEJ ALL  30-71-00 
　
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