Unit And System Checkout - Zehnder Rittling HP Series Installation, Operation And Maintenance Manual

Unit and system checkout

To avoid possible damage to a
plastic (PVC) piping system, do
not allow temperatures to exceed
110 ºF (43 ºC).
Before powering system,
please check the following:
Unit checkout
Filter: Clean or replace filter, if
n n
required.
Balancing/shutoff valves:
n n
Ensure that all isolation valves
are open and water control
valves are wired properly.
Line voltage and wiring:
n n
Verify that voltage is within an
acceptable range for the unit
and wiring and fuses/breakers
are properly sized. Verify that
low voltage wiring is complete.
Unit control transformer:
n n
Ensure that transformer has the
properly selected voltage tap.
Unit controls: Verify that the
n n
microprocessor DIP switches
are set for proper operation
and system configuration and
the thermostat is properly
configured.
Entering water and air:
n n
Ensure that entering water and
air temperatures are within
operating limits of Tables 10
and 11.
Low water temperature DIP
n n
switch: Verify that low water
temperature DIP switch on the
PCB controller is properly set.
Unit fan: Manually rotate fan to
n n
verify free rotation and ensure
that blower wheel is secured
to the motor shaft. Be sure to
remove any shipping supports
if needed. Do not oil motors
upon start-up. Fan motors are
pre-oiled at the factory.
Fan wheel blades are sharp.
Condensate line: Verify that
n n
condensate line is open and
properly pitched toward drain.
Water flow balancing: Record
n n
inlet and outlet water temperatures
and pressures for each heat pump
upon startup. This check can
eliminate nuisance trip outs and
high velocity water flow that could
erode heat exchangers.
Unit air coil and filters: Ensure
n n
that filter is clean and accessible.
Clean air coil of all manufacturing
oils.
System checkout
System water temperature:
n n
Check water temperature for
proper range and verify heating
and cooling setpoints for proper
operation.
System pH: Check and adjust
n n
water pH if necessary to maintain
levels indicated in Table 6. Proper
pH promotes longevity of hoses
and fittings.
System flushing: Verify that
n n
all hoses are connected end to
end when flushing to ensure that
debris bypasses the unit heat
exchanger, water valves and other
components. Water used in the
system must be potable quality
initially and clean of dirt, piping
slag, and strong chemical cleaning
agents. Verify that all air is purged
from the system. Air in the system
can cause poor operation or
system corrosion.
Cooling tower/boiler: Check
n n
equipment for proper setpoints and
operation.
Standby pumps: Verify that
n n
the standby pump is properly
installed and in operating
condition.
System controls: Verify that
n n
system controls function
and operate in the proper
sequence.
Low water temperature
n n
cutout: Verify that low water
temperature cut-out controls
are provided for the outdoor
portion of the loop. Otherwise,
operating problems may occur.
System control center: If
n n
applicable, verify that the
control center and alarm panel
have appropriate setpoints and
are operating as designed.
Miscellaneous: Note any
n n
questionable aspects of the
installation.
Verify that ALL water control
valves are open and allow
water flow prior to engaging the
compressor. Freezing of the coax
or water lines can permanently
damage the heat pump.
To avoid equipment damage,
DO NOT leave system filled in
a building without heat during
the winter unless antifreeze is
added to the water loop. Heat
exchangers never fully drain by
themselves and will freeze unless
winterized with antifreeze.
Unit and system checkout 35