Starting The Unit; Shut-Down The Unit; Safety Control; Functions - Midea MRCT-075CWN1-D(C) Technical & Service Manual

Midea R410A Tropical ClimaCreator Series Rooftop Package 220V 3Ph 60Hz
shafts?

Are all covers and access panels in place to prevent air loss and safety hazards?

Starting the unit:


When the unit operates under cooling mode, please check the line voltage of the unit. The
voltage should be within the range shown on the unit nameplate.

If low voltage is encountered, check the size and the length of power supply wire from the mian
disconnect to the unit. The line may be undersized for the length of the run.

Shut-down the unit:


Place the system selector in the OFF position or reset thermostat (Wired controller) at a setting
above room temperature.

Do not de-energize the main power supply disconnect except when unit is to be serviced.

9. Safety control

Functions


Minutes delay for the compressor start-up:
At the beginning of energizing, 3-minutes delay should be taken to start the compressor. While
after the stop of the compressor, 7-minutes delay should be taken to restart the compressor.

Compressor discharge temperature protection:
When the temperature of compressor discharge is higher than 125° C (257° F), the compressor
will stop. Once the temperature is lower than 90° C (194° F), the compressor can be started
again.

Reverse phase protection relay:
The reverse phase protection relay will make the unit not start, when the power supply source is
in correctly conneted.
The checking of phase order is just carried out at the first time of electrifying. If malfunction
happens then the checking will be going on until the order of phase is right, and the error code
will be displayed on the board. If there is no problem in the first checking, then it will be omitted.

High pressure and low pressure protection :
When high pressure is equal or higher than 638 Psi, and lower pressure is equal or lower than
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MCAC-RTT6S-201701