Start-Up; Preliminary Check - Johnson Controls CWP Manual De Instalación Y Mantenimiento

Start-up

5 START-UP
The first start-up of the unit, with a cooling
capacity equal to or greater than 17 kW,
shall be performed by an Authorised After-
Sales Service Centre. Failure to meet this re-
quirement will immediately void the warran-
ty.
The operations carried out by Itelco-Clima
personnel are limited to the start-up of the
unit, and do not include any other opera-
tion on the plant, such as, for example,
electrical and hydraulic connections etc. All
the other operations before start-up, includ-
ing oil pre-heating for at least 12 hours,
must be performed by the Installer..

5.1 Preliminary check

The checks listed below shall be performed before
starting the unit and before the arrival of the person-
nel authorised by Itelco-Clima.
Check the section of power supply and grounding
h
cables; make sure that terminals are tightened and
check the correct operation of contactors, with the
master switch open.
Check that any voltage and phase variation in the
h
power supply does not exceed the prefixed thresh-
olds.
Connect the contacts of the flow meter and the
h
thermal relay of the pump and of the other devices
(if any), to terminals 7-8 and 9-10, respectively.
Check that the components of the external water
h
circuit (pump, user equipment, filters, power sup-
ply tank and reservoir, if any) have been installed
properly, and according to the manufacturer's in-
structions.
Check the filling of the hydraulic circuits, and
h
make sure that the fluid circulation is correct, with-
out any trace of leaks and air bubbles. If you use
ethylene glycol as antifreeze, check that its per-
centage is correct.
Check that the direction of rotation of the pumps is
h
correct, and that fluids have been circulating for at
least 12 hours for both pumps. Then, clean the fil-
ters on the suction side of the pumps.
Adjust the liquid distribution network in such a
h
way that the flow rate is within the specified
range.
Page 14
Check that the water quality is up to the specifica-
h
tions.
Check that oil heaters, if any, have been turned on
h
at least 12 hours before.
5.2 Start-up
Start-up sequence:
Turn on the master switch (at least 12 hours be-
h
fore).
Check that the oil in the compressor has reached
h
the requested temperature (the minimum tempera-
ture outside the pan must be approx. 40°C) and
that the auxiliary control circuit is energised.
Check the operation of all the external equipment,
h
and make sure that the control devices of the plant
are properly calibrated.
Start the pump and check that the water flow is
h
correct.
Set the desired fluid temperature on the control
h
board.
Start the appliance (see Chapter 6).
h
Check the correct direction of rotation of compres-
h
sors. Scroll compressors cannot compress the re-
frigerant when they rotate in the opposite direc-
tion. To make sure that they are rotating in the cor-
rect direction, simply check that, just after the start-
up of the compressor, the pressure drops on the LP
side and rises on the HP side. Furthermore, if a
scroll compressor rotate in the opposite direction,
there is a considerable rise in the sound level of
the unit, as well as in a dramatic reduction of cur-
rent absorption compared to normal values. In
case of wrong rotation, the scroll compressor can
be definitely damaged.
After about 15 minutes of operation check that
h
there are no bubbles, through the sight glass on
the liquid line.
The presence of bubbles may indicate that
a part of the refrigerant charge has been re-
leased in one or more points. It is important
to remove these leaks before proceeding.