Fast IDRA-RSC Series Installation and maintenance manual - page 21
Air cooled water chillers and heat pumps with radial fans
IDRA - RSC Series
Use, installation and maintenance manual
21
GB
WIRING CONNECTIONS
The inlet for the electrical feeding cables is shown in the dimensional drawings. Remove the front panel in the upper part
of the unit to access the electric board; refer to the power and current values indicated in the present manual to size the
electrical feeding cables. The electrical wiring drawings, with all the remaining documentation present in the compressor
cabinet, are supplied with the unit.
Pay special attention to the following:
- only qualifi ed personnel are entitled to access and operate with the wiring connections;
- protect the electrical feeding cables against short-circuit and overload with protection devices as per law in force;
- choose a cable section conforming the protection device and considering all the possible infl uencing factors (tempera-
ture, insulation, length ect.);
- Perform all the operations to put the unit to earth with the utmost care;
- check if the electrical feeding system is 3-phases or 3-phases with neutral wire.
A couple of terminals (free-contacts), one for the remote general alarm and one for the remote ON-OFF, are present in
the terminal plate of the electric board.
Pay particular attention to the electrical wirings drawings, supplied with the units, when connecting a condensing
unit to the internal unit and to the room thermostat
START UP
Before starting the unit check the electric, hydraulic and cooling circuits.
Preliminary checks - electric circuit
Before proceeding with the checklist reported below, be sure that the electric feeding line is disconneted and the discon-
nection switch is locked. Proceed as follows:
- remove the front panel in the upper part of the unit;
- turn the main switch to “0” (OFF);
- open the door of the electrical board;
- verify that the feeding cables have been correctly sized;
- verify that the unit has been correctly put to earth;
- verify the tightening of the bolts that fi x the wires to the electrical components present in the electric board.
- close the door of the electric board.
It is possible now to feed the unit connecting the feeding line through the disconnection switch and turning the main
switch to “1” (ON). Using a voltmeter check the values of the phase tension; the value must be 400 V ± 10%.
Calculate the mean value of the phase tension (RS+ST+RT)/3 and the proportional difference between each of the phase
tensions and the calculated mean value. The maximum difference must not exceed 3%. The warranty will no longer be
valid with higher values.
EXAMPLE:
R-S = 397 V ; S-T = 406 V ; R-T = 395 V mean value: (397+406+395)/3 = 399,3 V
proportional difference:
(406 - 397) / 399,3 x 100 = 2,25%
(406 - 395) / 399,3 x 100 = 2,75%
(397 - 395) / 399,3 x 100 = 0,5%