Sterling RT - Manual (Page 13)

13
Figure 11 - Disconnect Box Locations
DX COIL EQUIPPED UNITS (OPTIONAL)
See Coil Installation/Maintenance Manual for Refrigerant
Piping, Liquid and Suction Line Components, Refrigerant
Charging and Thermal Expansion Valve Adjustment.
Remove coil cabinet access door located next to blower
section. Cut holes in fi xed door to allow suction and liquid
line passage. Provide weatherproof seal around suction
and liquid lines at piping plate when installed.
The DX Coil has a 300 ft/min. (1.524 m/s) minimum and
a 600 ft/min. (3.048 m/s) maximum velocity through the
coil requirement. This is due to prevention of coil icing or
condensate blow-off. To calculate the velocity through the
coil, apply the following formula:
Velocity = Cooling Air Flow in CFM (m 3 /s)
through the coil Coil Surface Area in ft 2 (m 2 )
Condensate Drain piping must have a P-trap in line
immediately downstream of drain pan connection, external
to the unit, to prevent possible outside air leakage into unit.
The P-trap shall be of suffi cient differential to overcome
negative pressure of the indoor air blower. A minimum
height difference of 2 inch is required (See Figure 12).
Before unit operation begins, the P-trap must be primed
with either water (summer) or glycol (winter).
CHILLED WATER COIL EQUIPPED UNITS (OPTIONAL)
See Coil Installation/Maintenance Manual for General
Coil Piping Recommendations. Remove the coil cabinet
door and cut holes in door to allow chilled water piping
passage. Provide weatherproof seal around chilled water
pipes at piping plate when installed.
The Chilled Water Coil has a 600 ft/min (3.048 m/s)
maximum velocity through the coil requirement. This is
due to prevention of condensate blow-off. To calculate
the velocity through the coil apply the following formula:
Velocity = Cooling Air Flow in CFM (m 3 /s)
through the coil Coil Surface Area in ft 2 (m 2 )
Condensate Drain piping must have a P-trap in line
immediately downstream of drain pan connection,
external to the unit, to prevent possible outside air leakage
into unit. The P-trap shall be of suffi cient differential to
overcome negative pressure of the indoor air blower.
A minimum height difference of 2 inch is required (See
Figure 12). Before unit operation begins, prime P-trap with
either water (summer) or glycol (winter).
Figure 12 - Drain Pan Connection
EVAPORATIVE COOLER
EQUIPPED UNITS (OPTIONAL)
Refer to Evaporative Cooler Installation and Service
Manual for water and electrical connections.
UNIT
2" MIN.
DRAIN PAN CONNECTION
D3887