Compressor Start Delay - Raypak 3450 Installation And Operation Manual

Compressor Start Delay

The control is equipped with a compressor start delay
to prevent short-cycling of the compressor.
control will not energize a compressor unless the
compressor has been off for at least 3 minutes. When
this situation arises, the display shall read "Comp Start
Delay" until the timer clears and the compressor starts.
Minimum Run Time
To ensure proper operation of the compressor and
longest life, the control has a minimum run time for
the compressor of 3 minutes. If the setpoint is reached
within 3 minutes, the compressor will continue to run
for 3 minutes unless (1) the high pressure switch trips,
(2) the water pressure switch trips, (3) the high tem-
perature limit is reached, or (4) the user selects "OFF"
mode.
Defrost Operation
The control is equipped with several defrost algorithms
depending on the configuration of the unit (HEAT
ONLY, POWER DEFROST or HEAT/COOL).
On HEAT ONLY models, the control initiates a defrost
cycle when the coil temperature falls to the "Defrost
Temp" setpoint (24°F (-4.4°C) default) established in
the Installer/Service sub-menu. The compressor will
shut off, but the fan will continue to operate to pull
warmer air across the coil in an effort to defrost the
coil. When the control sees a rise in the coil sen-
sor temperature equal to "Defrost Temp" + "Defrost
Deadband" (10°F (5.5°C) default) or after 15 minutes
have passed, the unit will exit the defrost cycle and
will return to normal heating operation based on the
current water temperature and setpoint temperature.
On POWER DEFROST models, the control initiates
a defrost cycle when the coil temperature falls to
the "Defrost Temp" setpoint (35°F (1.6°C) default)
established in the Installer/Service sub-menu. The
compressor will continue to operate (as well as the
fan) and a solenoid valve will open allowing a portion
of the hot refrigerant gas to bypass the heat exchang-
er and be directed back to the coil to warm the coil
for defrost. When the control see a rise in the coil
temperature equal to the "Def Terminate" value estab-
lished in the Installer/Service sub-menu (50°F (10°C)
default), the solenoid valve will shut and the unit will
return to normal heating operation based on the cur-
rent water temperature and setpoint temperature.
On HEAT/COOL models, the control initiates a defrost
cycle based on a programmed algorithm involving
current and baseline ambient temperatures, and cur-
rent and baseline coil temperatures when the coil
temperature drops below the "Defrost Temp" set in
the Installer/Service sub-menu. Factory default is 35°F
(1.6°C). The control shuts off the fan and activates the
reversing valve so the hot refrigerant gas is directed to
The
the coil to defrost the coil. When the coil sensor sees
temperatures above the "Def Terminate" value set in
the Installer/Service sub-menu, the unit returns to nor-
mal operation based on the current water temperature
and setpoint temperature.
NOTE: On Power Defrost and Heat/Cool models
the initial defrost after power ON is a "sacrificial"
defrost where the coil might freeze up more than
expected. The control is learning the parameters
of the installation to establish clear coil temperature
conditions for future defrost operation.
3-Way Valve Control
NOTE: Pump operation must be enabled through
Service/Installer Sub-Menu to operate 3-way valves
- whether or not the HPPH control will actually
control the pump or not.
The control is equipped to operate system 3-way
valves. The control will set the 3-way valves to the
state requested when there is an active thermostat
demand for spa heat, pool heat or pool cool AND
when Pump operation is enabled through the control.
This takes priority over positions requested by Pump
Schedule operations. If the control also operates the
pump, the pump will shut off for 30 seconds before the
valves change state so as to not have to fight pump
head pressure during change of position. During this
change, the display will show "Valve Chng Delay".
The 3-way valves are field installed to the #38-40
& #41-43 terminals on the terminal strip inside the
junction box of the unit. The initialization of the 3-way
valves is set in the Installer/Service sub-menu.
If the water pressure switch (or water flow switch) is
closed when the control needs to change the 3-way
valve position, the control displays "WPS Closed"
and waits indefinitely with the pump and compressor
off until the water pressure switch (water flow switch)
opens. After it senses the open switch, the control
switches the 3-way valves and resumes normal oper-
ation.
If no thermostatic demand is requesting operation and
the pump is being run from scheduled pump periods,
the control sets the 3-way valves to the states request-
ed in the pump period mode schedule.
When there is no demand for pump output because of
manually selected OFF mode, no thermostat demand
or no scheduled pump period, the control leaves the
3-way valves in their last commanded state. Valve
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