Westric DW Series, Инструкция по установке, эксплуатации и обслуживанию

Страница: 32 / 48

76-1002-00 Page 32 of 48
AUTOMATIC/MANUAL START UP
For a better understanding of the operation, we will call it aut/man.
For boards with PLCs, Aut/man control is a key that, when pressed, will disconnect the PLC
Therefore, the automatic control (PLC controller) is disconnected and the unit begins to run manually.
The manual mode must only be used when the PLC is not operating. While in manual mode, the unit must be
monitored by qualified staff. Manual mode has only basic protections and no time delays.
Sensor description
Inputs may vary depending on different configurations of air conditioners.
Digital inputs are as follow:
A) Safety Inputs

TVE Thermal relay of evaporator blower

TVC Thermal relay of condenser blower

TC Thermal relay of compressor

PB Low-pressure switch

PA High-pressure switch

FF Missing phase, low or high voltage, and phase symmetry

Blind end switch
B) Mechanical thermostat input.
This thermostat is totally independent from automatic control.
Operation
While in manual mode, if all safety sensors are operating under normal conditions, the evaporator blower will be
switched on.
If all safety features are operating properly, the system will rely on the manual thermostat. If the manual thermostat
closes (because room temperature exceeds the temperature value set on the thermostat) the compressor and the
condenser blower will be switched on.
Does not work on AUT/MAN.
Once this selector has been pressed, but the unit still does not work in Manual
mode, check whether some of the protective elements are not open. (e.g., low, high pressure switches, relays, etc.)
Check if room temperature is above 24ºC, so the thermostat is switched on. Check mechanical thermostat, also
that there is electrical continuity between terminals, once the above mentioned item has been checked.