RTAC-SVX01F-EN 147
Unit Shutdown Procedures

Temporary Shutdown And Restart

To shut the unit down for a short time, use the following procedure:
1. Press the STOP key on the CH530. The compressors will continue to operate
and, after an unloading period (which may be followed by pumpdown cycle in out-
door ambients below 50oF), will stop when the compressor contactors de-ener-
gize.
2. CH530 pump control will turn off the pump (after a minimum 1 min. delay) when
the STOP key is pressed and automatically restart the pump when the unit starts
normally.
3. The unit will start normally, provided the following conditions exist:
– The CH530 receives a call for cooling and the differential-to-start is above the
setpoint.
– All system operating interlocks and safety circuits are satisfied.

Extended Shutdown Procedure

The following procedure is to be followed if the system is to be taken out of service
for an extended period of time, e.g. seasonal shutdown:
1. Test the unit for refrigerant leaks and repair as necessary.
2. Open the electrical disconnect switches for the chilled water pump. Lock the
switches in the “OPEN” position.
CAUTION

Chilled Water Pump!

Lock the chilled water pump disconnects open, to prevent pump
damage.
3. Close all chilled water supply valves. Drain the water from the evaporator.
4. With the water drained from evaporator, the "customer provided" power for the
120-volt evaporator heaters (terminated at 1TB4...terminals 1 & 2) must be must
disconnect.
These heaters consist of 1 well heater in each evaporator end (or water box), and
the heat tape, which is wrapped around the bundle itself. They are energized by a
klixon temperature control mounted on the side of the evaporator, which
energizes at or below 37oF. outside air temp. If there is no liquid in the evaporator
and the temp drops below 37 degrees, both of the well heaters will burn up
because they have no liquid to transfer their heat into.
5. Open the unit main electrical disconnect and unit-mounted disconnect (if
installed) and lock on the “OPEN” position. If the optional control power trans-
former is not installed, open and lock the 115V disconnect.