Table of Contents
Advertisement
If the HPWH does not start immediately:
•
Wait 5 minutes in case the anti short cycle timer has
halted operation. This control system feature protects
the HPWH from rapid short cycling that can cause
permanent damage to the unit.
•
Ensure the operating set point on the tank temperature
control is adjusted high enough to initiate a call for
heat. The recommended setting is 120°F to 150°F
(29°C to 66° C).
•
DO NOT set the operating set point on the tank
temperature control above 150°F. See Water
Temperature Range on page 4.
•
Ensure the Diff erential Set Point is not set too high.
Higher differential settings will cause greater
temperature swings in system temperature. Lower
diff erential settings can cause unit short cycling. The
recommended setting is 10°F.
•
If the unit does not start after all of the above procedures
have been followed. Refer to the troubleshooting
section of this manual.
4.
Securely attach surface mount thermometers or temperature
sensors to the inlet (entering) and outlet (leaving) water
lines near the HPWH cabinet. If there are thermometers
installed in the inlet and outlet in close proximity to the
HPWH water connections they can be used for the following
check. Ensure the water outlet (supply) and inlet (return)
valves are fully open. Start the HPWH and allow it to
operate for 5 minutes. with the HPWH operating record
the inlet and outlet temperatures.
During normal operation, the outlet line should be 8°F
to 12°F (4°C to 7°C) hotter than the inlet line. This is the
temperature rise through the heat exchanger inside the
HPWH unit. Note: Temperature rise and water fl ow rate
through the heat exchanger inside the HPWH are
uniformly linked. As water fl ow is decreased the temperature
rise will increase and as water flow is increased the
temperature rise will decrease. Because of this relationship
between temperature rise and fl ow rate this test can be
useful to determine if the flow rate through the heat
exchanger is adequate. Other factors may also aff ect water
fl ow rate and temperature rise such as debris or lime scale
build up inside heat exchanger or water pump operation.
If the temperature rise through the HPWH is consistently
lower than 8°F the outlet (supply) valve can be throttled
slightly closed to reduce the water fl ow rate. This may be
necessary on installations with a minimum of water piping
between the HPWH and the water system or tank.
Throttling should be done in small increments, no more
than 1/8 turn of the valve handle at a time. The HPWH
must be allowed to run for approximately 5 minutes
between each adjustment before the temperature rise
is measured again. If the outlet valve is throttled during
20
start up, mark the valve position and remove the valve
handle to ensure it is not accidentally changed.
If the temperature rise through the HPWH is consistently
greater than 12°F the water fl ow may be restricted. Ensure
all water valves between the HPWH and the tank or water
system are fully open. Ensure the e x t e r n a l water pump
is running. If the temperature rise continues to be excessive
call the toll free technical support phone number:
447-3201.
5.
Using thermometers or temperature sensors, measure
the temperature of the incoming source water to the
HPWH and the outgoing source water leaving the unit.
The outgoing temperature should be 12°F to 20°F (7°C to
13°C) cooler than the incoming. The higher the fl ow rate
the lower the temperature diff erential will be
6.
When all of the above procedures are complete adjust
the tank temperature control set point to desired system
temperature, not to exceed 150°F (66°C). Remove all test
instruments and replace all cabinet doors.
PROGRAMMABLE LOGIC CONTROLS
PLC CONTROLLER
Your unit may be equipped with a Programmable Logic Controller
(PLC) and Human-Machine Interface (HMI) for controlling the
water heating process. Sensors within the system provide
operating information to the PLC which uses this information
to safely control the heating process. The control comes with a
pre-set water high temperature setpoint of 120°F. The control
is limited to a maximum water high temperature setpoint of
160°F. Operating at higher temperatures could void the warranty.
TEMPERATURE & SETPOINTS
To view and adjust the temperature setpoint, follow these
steps.
•
View the HMI mounted on the electrical panel door.
Locate the "High Temp" value on the setup screen.
•
Touch the box representing the current value. A keypad
and cursor will appear.
•
Enter the desired temperature setpoint (maximum 160°F)
•
Touch the return, or enter key on the keypad. The
display will return to the info screen, and your entered
value should be displayed in the "high Temp" value box.
The unit is now set to heat up to the new setpoint
temperature.
Note: Until the Return key is pressed, the unit will run
based upon the previous setpoint temperature.
1-833-
Advertisement
Table of Contents
