Rheem 325 II Series Service Instructions Manual page 10

Evaporator – An aluminium finned copper coil where the low pressure, low temperature
refrigerant absorbs heat from the surrounding ambient air. As the refrigerant absorbs heat
and becomes warmer, it evaporates (changes state) to a saturated vapour. Heating of the
saturated refrigerant vapour continues such that it becomes superheated.
Filter Drier – A component fitted in the refrigerant liquid line. The filter drier traps
impurities and removes moisture from the sealed refrigeration system.
Fitting Liner – A plastic tube installed in the cold water inlet of the storage tank to provide
protection against corrosion through the life of the water heater.
Heating Element – A tubular device containing a resistive element, that converts electrical
energy to heat.
Outlet Delivery Tube (Dip Tube) – A plastic tube installed in the hot water outlet of the
water heater cylinder to conduct water from the highest point to the outlet connection. It
also acts as a fitting liner.
Pressure Limiting Valve (PLV) – A valve that controls its outlet pressure to a
predetermined limit.
Process Tube – A short piece of copper pipework used for charging refrigerant into the
refrigeration system during manufacture.
Refrigerant High Pressure Switch – A pressure switch in the refrigerant discharge line
that opens when the refrigerant discharge pressure exceeds the switch rating.
Sensor – A device which changes resistance with a change in temperature, also known as
a thermistor. Sensors are used to measure temperature and feed the information back to a
control system.
Sight Glass – A component fitted in the refrigerant liquid line. The sight glass allows the
state (liquid/vapour) of the passing refrigerant to be observed, and includes a moisture
indicator.
Suction Accumulator – A device fitted in the refrigerant suction line, which accumulates
and prevents any liquid refrigerant from entering and damaging the compressor. Any liquid
refrigerant in the suction accumulator is evaporated or "boiled off" to a vapour.
Temperature and Pressure Relief (T&PR) Valve – A valve designed to provide
automatic relief by discharging water in case of excessive temperature, pressure or both.
Never fit a T&PR Valve with a pressure rating greater than that indicated on
the product rating label.
Thermal Cut Out (ECO) – A manually reset temperature sensitive device mounted
against the water heater cylinder, which cuts off the supply of electrical energy.
Thermostat – A temperature sensitive device mounted against the water heater cylinder,
which controls the supply of electrical energy to maintain the stored water at the required
temperature.
Thermostatic Expansion (TX) Valve – A mechanical valve that expands the liquid
refrigerant to a lower pressure as it moves through the TX valve‟s orifice. The expansion
process also lowers the temperature of the refrigerant, to a point below that of the
surrounding ambient air. The TX valve has a bulb that senses the temperature of the
suction line at the evaporator outlet. The TX valve thermostatically meters the flow of
expanding refrigerant to the evaporator, in response to the temperature of the suction line
as measured by the bulb.
TM077: 325 & 410 Series II Heat Pump Service Instructions
Rev 00: Issued April 2014
This document is stored and maintained electronically by Service. All printed copies are deemed uncontrolled.
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