York YCAS0130 Switch Settings, Compressor Heaters, Water System, Flow Switch, Temperature Sensors

Check that the tapping used conforms to the site supply voltage. After the tapping is verified, replace the lid.

Switch Settings

Ensure that the unit ON/OFF switch on the display door and the micro board system switches S2 through S5 are set to “0” (OFF). Set the red handled emergency stop device on the options panel to “1” (ON). For units fitted with door interlocked circuit breakers the power panel doors must be closed and the devices set to “1” (ON). The customer’s power disconnection devices can now be set to ON.

The machine is now live!

The unit is fitted with an under voltage circuit in each panel and it may take between 5 to 10 seconds for its contacts to close and energize the unit’s electronics, including the display on the main panel.

Compressor Heaters

Verify the compressor heaters are energized. If the ambient temperature is above 96°F (36°C) the compressor heaters must be on for at least 8 hours before start-up to ensure all refrigerant liquid is driven out of the compressor. If the ambient temperature is below 86°F (30°C) then allow 24 hours.

Water System

Verify that the chilled liquid system has been installed correctly, and has been commissioned with the correct direction of water flow through the evaporator. The inlet should be at the refrigerant pipework connection end of the evaporator. Purge air from the top of the evaporator using the plugged air vent mounted on the top of the evaporator body. Flow rates and pressure drops must be within the limits given in the Technical Data Section. Operation outside of these limits is undesirable and could cause damage.

Flow Switch

Verify a chilled water flow switch is correctly fitted in the customer’s pipework on the evaporator outlet, and wired into the control panel correctly using shielded

FORM 201.19-NM1 (204)

cable. There should be a straight run of at least 5 pipe diameters on either side of the flow switch. The flow switch should be connected to terminals 13 and 14 in the micro panel (Figs. 13 and 14, pages 40 and 41).

Temperature Sensor(s)

Ensure the leaving liquid temperature sensor is coated with heat conductive compound (part no. 013-00890-

000)and is inserted in the water outlet sensor pocket of the evaporator. This sensor also acts as the freeze protection thermostat sensor and must always be in the water OUTLET sensor pocket.

Control Supply

Verify the control panel display is illuminated.

Programmed Options

Verify that the options factory programmed into the Microcomputer Control Center are in accordance with the customer’s order requirements by pressing the ‘Op- tions’ key on the keypad and reading the settings from the display.

Programmed Settings

Ensure the system cut-out and operational settings are in accordance with the instructions provided in Section 8 (page 166) and with the general chiller op- erational requirements by pressing the ‘Program’ key. The chilled liquid temperature control settings need to be set according to the unit model and required oper- ating conditions.

Date and Time

Program the date and time by first ensuring that the CLK jumper J18 on the microprocessor board is in the ON position (top two pins). Then press the ‘Clock Set Time’ key and set the date and time. (See Section 7.)

Start/Stop Schedule

Program the daily and holiday start/stop by pressing the ‘Set Schedule/Holiday’ key. (See Section 7.)

Setpoint and Remote Offset

Set the required leaving chilled liquid temperature setpoint and control range. If remote temperature reset (offset) is to be used, the maximum reset must be pro- grammed by pressing the ‘Remote Reset Temp’ key. (See Section 6.)

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YORK INTERNATIONAL 43