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All 2.5 to 5 ton three phase split system cooling units and heat pumps are shipped from
the factory with compressor crankcase heat. Three phase compressor do not require
start capacitors or start relays.
CCHT - Compressor Crankcase Heater, sometimes called a compressor sump heater.
This device is designed to warm the compressor crankcase (or sump) in order to prevent
or deter refrigerant migration during the compressor off cycle. Compressor crankcase
heaters are required for low ambient cooling operation.
TXV - Thermostatic Expansion Valve. This is a type of refrigerant flow control device
designed to maintain constant superheat throughout the operating envelope. For low
ambient cooling applications, a non-bleed TXV is required.
Bleed TXV: This type of TXV will allow the refrigerant pressures between the high side
and low side to equalize through the valve during the off cycle.
Non Bleed TXV: This type of TXV will not allow the refrigerant pressures between the
high side and low side to equalize through the valve during the off cycle. When using this
type of valve on single phase units with reciprocating style compressors, compressor
start components are required. Check product data specifications for most current infor-
mation.
Head pressure controller -Adevice that is field installed on a condensing unit or heat
pump designed to maintain system head pressure that will allow safe system operation
without indoor coil icing in colder outdoor ambients. The BAYLOAM*** will cycle the
condenser fan motor in order to achieve adequate operating head pressure. The control
isadjustable.
Evaporator Defrost Control -Adevice that is field installed on the system’s indoor coil
in order to prevent the system from running during the cooling cycle when the indoor coil
approaches or reaches a temperature in which frost will form on the coil surface. When
the indoor coil approaches a safe temperature for cooling operation, the control will close
and allow the outdoor unit to restart. This controller makes and breaks the control volt-
age to the condensing unit.
Quick Start Component - This component may be factory installed or offered as a field
installed accessory ( BAYKSKT***). A quick start kit consist of a capacitor with a high
microfarad rating and a potential relay. It is installed so that the start capacitor is wired in
parallel with the compressor’s run capacitor. Prior to start-up the potential relay contacts
are closed, therefore placing the start capacitor in the compressor circuit, as the com-
pressor motor reaches operating speed, electrical current flows through the potential
relay’s coil and the the relay contacts are opened, thus taking the start capacitor out of
the system until the next compressor start up.
Definitions and information:
Three phase products:
Section I - Terms and Definitions:
