Water Furnace 502W12 Installation Manual - Legend
24
5 SERIES 502W12 INSTALLATION MANUAL
HE
gpm x 500*
Legend
Reference Calculations
Heating Calculations:
Cooling Calculations:
LWT = EWT +
HR
gpm x 500*
LWT = EWT -
NOTE:
* When using water. Use 485 for 15% methanol/water or Environol solution.
ABBREVIATIONS AND DEFINITIONS:
COP = coefficient of performance (HC/kW x 3.413)
EER
= cooling energy efficiency (TC/kW)
ELT
= entering load fluid temperature to heat pump
EST
= entering source fluid temperature to heat pump
ft HD = pressure drop in feet of head
HC
= heating capacity in MBtu/h
HE
= total heat of extraction, MBtu/h
HR
= total heat of rejection, MBtu/h
kW
= total power unit input, kilowatts
Lgpm = load flow in gallons per minute
LLT
= leaving load fluid temperature from heat pump
LST
= leaving source fluid temperature from heat pump
LWPD = load heat exchanger water pressure drop
psi
= pressure drop in pounds per square inch
Sgpm = source flow in gallons per minute
SWPD = source heat exchanger water pressure drop
TC
= total cooling capacity in MBtu/h
Verify the following:
• High voltage is correct and matches nameplate
• Fuses, breakers and wire size are correct
• Low voltage wiring is complete
• Piping is complete and the water system has been
cleaned and flushed
• Air is purged from closed loop system
• Isolation valves are open and water control valves or loop
pumps are wired
• Service/access panels are in place
• Transformer has been switched to lower voltage tap if
needed (208/230 volt units only)
• Unit controls are in “off” position
• Flow switches are installed and ready
• Freeze detection setpoints have been set in
the microprocessor
WARNING: Verify ALL water controls are open
and allow water flow PRIOR to engaging the
compressor. Failure to do so can result in freezing
the heat exchanger or water lines causing
permanent damage to the unit.
Unit Startup
Startup Steps
• Set thermostat control above cooling setpoint.
• Set thermostat control in cooling mode.
• Slowly reduce the control setting until both the
compressor and water control valve/loop pumps are
activated. Verify that the compressor is on and that
the water flow rate is correct by measuring pressure
drop through the heat exchanger and comparing to the
Pressure Drop table. Check for correct rotation of scroll
compressors. Switch any two power leads at the L1, L2,
and L3 line voltage termination block if incorrect.
• Perform a cooling capacity test by multiplying gpm x
Δ
T
x 485 (antifreeze/water). Use 500 for 100% water. Check
capacity against catalog data at same conditions.
• Set control to “OFF” position.
• Leave unit “OFF” for approximately five (5) minutes to
allow pressure to equalize.
• Adjust control below heating setpoint.
• Set control in “HEAT” position mode.
• Slowly increase the control setting until both compressor
and water control valve/loop pumps are activated. The
reversing valve should be heard changing over.
• Perform a heating capacity test by multiplying gpm x
Δ
T
x 485 (antifreeze/water). Use 500 for 100% water. Check
capacity against catalog data at same conditions.
• Check for vibrations, noise and water leaks.
• Set system to maintain desired setpoint.
• Instruct the owner/operator of correct control and
system operation.