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TVP Manual (full) March 2007 CE rev 03.doc
2.50 Preparation for operation
The pressure in the refrigeration line / cryo-coil should be equal to the system balance
pressure (235 – 250 psi). Fully open the hand valves in this order – Defrost, Cool and
Common return (underneath the valve box cover inside the front door). Turn each valve back
¼ turn to prevent the valve sticking in an open position.
Allow 2 minutes for the pressures to equalise. Record the balance pressure from the system
display panel. It is expected that the pressure will have dropped. The optimal pressure range
is between 235 – 250 psi as displayed on the pressure gauge. If the pressure is higher than
this value refrigerant should be reclaimed through the access valve, if lower more gas should
be added using a reclaim unit to pump the gas in.
CAUTION
Achieving the correct system balance pressure is critical in maximising the potential of your
TVP too high a pressure will result in the system over pressure protection being activated, too
low and the maximum cooling capacity maybe compromised.
Replace the valve box cover including insulation, check that a good seal is made around the
whole of the box. This prevents frosting of the valves during operation.
Allow water to flow around the system, ensure the flow rate is sufficient for the inlet
temperature (See graph).
Apply power to system
Check all 3 phases are present and that they are roughly equivalent voltages. Damage maybe
caused if unit is run with missing / browned out phases.
The TVP requires no neutral, a circuit breaker with a value suitable for the maximum current
draw must be selected. A TVP is phase sensitive and may require the phases to be swapped
following initial start. The unit has phase protection software, which will cause the unit to stop
after about 10 seconds of reverse running is detected. Older models do not have phase
protection software.
WARNING
The system contains high voltage (208 or 415VAC) and high power components. To avoid the
possibility of a fatal electrical shock always isolate the unit from the mains supply before
working on the system. A qualified technician, as for all high power electrical connections,
should carry out the electrical work.
If the unit has the wrong phase orientation DP value will not rise, no damage can be caused
by short periods of reverse operation. Damage may be caused if you unit is left to run for
long periods running backwards.
CAUTION
Check the following before starting the unit.
Power is supplied to all 3 phases.
Water flow and temperature meet minimum system requirements (see graph)
All hand valves are open.
There is an audible beep followed by a click on power up to the display
DP/SP are balanced in the range 235 to 250psi (assuming CT is above 10
o
c) make a note of
these values