Compressor Crankcase Heaters; Symbio Controls - Trane Precedent YSJ072 Installation, Operation And Maintenance Manual

WARNING
Hazardous Voltage w/Capacitors!
Failure to disconnect power and discharge capacitors
before servicing could result in death or serious
injury.
Disconnect all electric power, including remote
disconnects and discharge all motor start/run
capacitors before servicing. Follow proper lockout/
tagout procedures to ensure the power cannot be
inadvertently energized. Verify with a CAT III or IV
voltmeter rated per NFPA 70E that all capacitors have
discharged.
1. 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
OFF.
2. Connect the phase sequence indicator leads to the
terminal block or to the line side of the optional factory
mounted disconnect switch as follows:
a. Brown (phase A) to L1
b. Orange (phase B) to L2
c. Yellow (phase C) to L3
3. Close the field supplied main power disconnect switch
or circuit protector switch that provides the supply
power to the unit.
Note: Upon closing main power disconnect and the unit
mounted disconnect switch or circuit breaker,
the phase monitor will verify proper phasing. If
LED on face of the monitor is red, correct supply
power fault.
WARNING
Live Electrical Components!
Failure to follow all electrical safety precautions when
exposed to live electrical components could result in
death or serious injury.
When it is 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.
Important: 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.
4. 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.
5. Restore the main electrical power and recheck the
phasing. If the phasing is correct, open the disconnect
RT-SVX071D-EN
switch or circuit protection switch and remove the
phase sequence indicator.

Compressor Crankcase Heaters

• Each compressor can be equipped with a crankcase
heater (Some units include crankcase heater as
standard). 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.
1. Before starting the unit in the cooling mode, flip the
system switch OFF.
2. Turn the main power disconnect ON and allow the
crankcase heater to operate a minimum of 8 hours.
1. Before closing the main power disconnect switch,
confirm the system selection switch is OFF and the fan
selection switch is in the AUTO position. 2.
2. Close the main power disconnect switch and the unit
mounted disconnect switch, if applicable.
Note: When closing main power disconnect and the unit
mounted disconnect switch or circuit breaker, the
phase monitor will verify proper phasing. If LED on
face of the monitor is red, correct supply power fault.
WARNING
Live Electrical Components!
Failure to follow all electrical safety precautions when
exposed to live electrical components could result in
death or serious injury.
When it is 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.
Important: 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.

Symbio Controls

The Symbio™ 700 supports a Service Test Mode that can
be used to energize the various components of the system,
either to support general system startup tasks or to support
Pre-Start
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