321 Studios QW2S Pager User Manual


 
F1915 (2012 04) Page 2 of 6
2.3 COMPRESSOR
All models shall use a high efficiency scroll compressor with step
capacity providing 2 stages of control. The compressor shall be
covered by a 5-year parts warranty. The refrigeration circuit shall be
equipped with factory installed high and low-pressure controls. The
refrigeration control shall be a factory installed TXV. Compressor
shall be mounted on isolation rails with double grommets. Unit shall
be provided with R-410A (HFC) non-ozone depleting refrigerant. Unit
shall be provided with liquid line filter/drier.
Current sensing relay shall be used to detect high amps caused by
high ambient and/or low voltage and to shift compressor to 1
st
-stage
operation until conditions corrected
2.4 COAXIAL WATER COIL
All models shall have either cupronickel or copper (SELECT ONE);
water coil, fully insulated, with double o-ring connections. Copper
coils should not be used on open wells.
2.6 INDOOR BLOWER MOTOR
The indoor blower motor shall be a variable speed (ECM) type to
produce the same rated airflow from 0 to .8 inch WC of external static
pressure (.5 on Q24W model) at low sound levels. The motor is to be
self-adjusting to provide proper rated airflow at high static pressures
without user adjustment or wiring changes by the user. The motor
shall be programmed for 20-second ramp up and 60-second down
rate for quiet, smooth starting and stopping. ECM motor shall
include preprogrammed speeds for ventilation mode, first stage
operation, second stage operation, ducted operation, and non-
ducted operation.
2.7 ELECTRICAL COMPONENTS
Electrical components are easily accessible for routine inspection
and maintenance through front service panels. Circuit breaker is
standard on all 208/230-volt models and rotary disconnect standard
on all 460-volt models. Circuit breaker/rotary disconnect access is
through lockable access panel. Lock and key are provided as
standard equipment. Unit shall have single point entry for line
voltage.
2.8 CONTROL CIRCUIT
The internal control circuit shall consist of a current limiting 24VAC
type 65VA transformer with circuit breaker. To prevent rapid
compressor short cycling, a five-minute time delay circuit shall be
factory installed. Two low-pressure controls shall be included as