Trane RTWA 70-125 TON - Manual (Page 86)

86 RLC-SVD03A-EN
Other Service Features
ƽ WARNING
Hazardous Voltage w/Capacitors!
Disconnect all electric power, including remote disconnects
before servicing. Follow proper lockout/tagout procedures to
ensure the power cannot be inadvertently energized. For variable
frequency drives or other energy storing components provided by
Trane or others, refer to the appropriate manufacturer’s literature
for allowable waiting periods for discharge of capacitors. Verify
with an appropriate voltmeter that all capacitors have discharged.
Failure to disconnect power and discharge capacitors before
servicing could result in death or serious injury.
Note: For additional information regarding the safe discharge of
capacitors, see PROD-SVB06A-EN or PROD-SVB06A-FR
NOTE: If it is necessary to service the circuit/ compressor while allowing
the opposite circuit to start and run, first temporarily disconnect all power to
the chiller and then disconnect all control power connections to the
compressor and associated controls, by pulling off all the control power
voltage connectors on the right hand side of the associated MCSP module.
Control power to the associated contactor should also be disconnected, as
should the power lead(s) to the high pressure switch at the control power
terminal block. Repower the chiller, and lockout the circuit you are servicing
by entering the Service Tests Menu and enabling CIRCUIT LOCKOUT for the
desired circuit. Placing the chiller switch into the Auto mode will then allow
the opposite circuit to run.
7. Return all valves to their normal position. temporarily remove all power
and reconnect all wiring when servicing is completed.
8. Reset the chiller to clear diagnostics (and diagnostic history if desired) to
resume normal operation.
COMPRESSOR TEST
The UCM provides for a Compressor Test feature which is designed to allow a
service-technician to direct a particular compressor to be the next
compressor to stage on, run and modulate. This allows the temporary
override of the lead/lag sequencing currently in effect and relieves the
technician from forcing staging of compressors thru load or setpoint changes.
It is important to note that invoking this feature does not put the chiller into
any kind of override "mode" and no action is required to return to "normal
operation". The chiller will continue to run normally and the current lead/lag
sequence will again be in effect, once the selected compressor has started.
This feature is used in the Slide Valve Checkout Procedure detailed in Slide
Valve Checkout Procedure.
Invoking Compressor Test
1. With the Chiller in the Auto Mode, regardless of whether or not other
compressors are currently running, use the CLD to enter the Service
Tests Menu and enable the COMPRESSOR TEST for the appropriate
compressor. The selected compressor will automatically stage on, once
the anti-recycle or restart inhibit timer is satisfied and the EXV is preposi-