Carrier PC211 specifications Cold Weather Operation

Carefully make all regular preliminary and running system checks. Perform a Control Test before start-up. If the compressor oil level appears abnormally high, the oil may have absorbed refrigerant. Make sure that the oil temperature is above 140 F (60 C) or cooler refrigerant temperature plus 50° F (27° C).

Cold Weather Operation

When the entering condenser water drops very low, the operator should automatically cycle the cooling tower fans off to keep the temperature up. Piping may also be arranged to bypass the cooling tower. The PIC controls have a low limit tower fan relay (PR3) that can be used to assist in this control.

Manual Guide Vane Operation

Manual operation of the guide vanes in order to check control operation or control of the guide vanes in an emergency operation is possible by overriding the target guide vane position. Access the Status01 table on the LID and highlight TARGET GUIDE VANE POSITION. To control the position, enter a percentage of guide vane opening that is desired. Zero percent is fully closed, 100% is fully open. To release the guide vanes to AUTOMATIC mode, press the RELEASE softkey.

Note: Manual control will increase the guide vanes and override the pulldown rate during start- up. Motor current above the electrical demand setting, capacity overrides, and chilled water below control point will override the manual target and close the guide vanes. For descriptions of capacity overrides and set points, see the Controls section.