Compressor Crankcase Heaters - Trane TC*150-301 Installation Operation & Maintenance

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Black (phase A) to L1
Red (phase B) to L2
Yellow (phase C) to L3
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Live Electrical Components!
During installation, testing, servicing and troubleshooting of this product, it may be necessary
to work with live electrical components. Have a qualified licensed electrician or other individual
who has been properly trained in handling live electrical components perform these tasks.
Failure to follow all electrical safety precautions when exposed to live electrical components
could result in death or serious injury.
To prevent injury or death from electrocution, it is the responsibility of the technician to recognize
this hazard and use extreme care when performing service procedures with the electrical power
energized.
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Compressor Crankcase Heaters

Each compressor can be equipped with a crankcase heater. The proper operation of the crankcase
heater is important to maintain an elevated compressor oil temperature during the "Off" cycle to
reduce oil foaming during compressor starts. Oil foaming occurs when refrigerant condenses in
the compressor and mixes with the oil. In lower ambient conditions, refrigerant migration to the
compressor could increase.
When the compressor starts, the sudden reduction in crankcase pressure causes the liquid
refrigerant to boil rapidly causing the oil to foam. This condition could damage compressor
bearings due to reduced lubrication and could cause compressor mechanical failures.
Before starting the unit in the "Cooling" mode, set the system switch to the "Off" position and turn
the main power disconnect to the "On" position and allow the crankcase heater to operate a
minimum of 8 hours.
Before closing the main power disconnect switch, insure that the "System"selection switch is in
the "Off" position and the "Fan" selection switch is in the "Auto" position.
Close the main power disconnect switch and the unit mounted disconnect switch, if applicable.
RT-SVX25C-EN
Turn the field supplied disconnect switch that provides power to the main power terminal block
or to the "Line" side of the optional factory mounted disconnect switch to the "Off" position.
Connect the phase sequence indicator leads to the terminal block or to the "Line" side of the
optional factory mounted disconnect switch as follows;
Close the field supplied main power disconnect switch or circuit protector switch that provides
the supply power to the unit.
WARNING
Observe the ABC and CBA phase indicator lights on the face of the sequencer. The ABC
indicator light will glow if the phase is ABC. If the CBA indicator light glows, open the disconnect
switch or circuit protection switch and reverse any two power wires.
Restore the main electrical power and recheck the phasing. If the phasing is correct, open the
disconnect switch or circuit protection switch and remove the phase sequence indicator.
Installation
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