Protecting The Unit From Frost; Electrical Connections - Hitecsa EWNLM 115 Manuel D'utilisation

II.5.4

PROTECTING THE UNIT FROM FROST

IMPORTANT!
If the master switch is open, it excludes the
electricity supply to the plate exchanger resistance
and the compressor guard resistance. This switch
should only be connected for cleaning,
maintenance or repair of the machine.
When the unit is running, the control board protects the heat-exchanger
from freezing by making the anti-freeze alarm cut in; stopping the
machine if the temperature of probe fitted on the heat-exchanger
reaches the set-point value.
IMPORTANT!
When the unit is out of service, drain all the water
contents from the circuits.
If the draining operation is felt to be too much trouble, ethylene glycol
may be mixed with the water in suitable proportions in order to
guarantee protection from freezing.
In the case of a small water flow in the rejection exchanger operating as
evaporator, and/or an excessively low inlet temperature, the ST3 probe
could trigger the antifreeze alarm.
If the machine is installed in a glycol and water loop, it is possible to
modify the set-point (using the password) on the basis of the
percentage of glycol used (see the table below).
IMPORTANT!
Mixing the water with glycol modifies the
performance of the unit.
Table "A" shows the multipliers which allow the changes in performance
of the units to be determined in proportion to the required percentage of
ethylene glycol.
The multipliers refer to the following conditions: condenser inlet water
temperature 30°C; chilled output water temperature 7°C; temperature
differential at evaporator 5°C. For different operating conditions, the
same coefficients can be used as their variations are negligible.
Maximum concentration of ethylene glycol accepted 30%.
Table "A":
Glycol in weight 10 %
FREEZING
TEMPERATURE -5
°C
fc QF 0,991
fc P 0,996
fc Δpw
1,053
fc G 1,008
fc QF = Cooling capacity correction factor.
fc P = Correction factor for the absorbed electrical power.
fc Δpw = Correction factor of the pressure drop in the evaporator
fc G = Correction factor of the glycol water flow to the evaporator
II.6

ELECTRICAL CONNECTIONS

DANGER!
Always install a general automatic switch in a
protected area near the appliance with a
characteristic delayed curve, with sufficient
capacity and breaking power. There should be a
minimum distance of 3 mm between the contacts.
Earth connection is compulsory by law to ensure
user safety while the machine is in use.
DANGER!
Electrical connection of the unit must be carried out
by qualified personnel in compliance with the
regulations in effect in the country where the unit is
installed. HITECSA shall not be held liable for
damage to persons or property caused by incorrect
electrical connection.
In making the electrical connections to the board,
cables must be routed so that they do not touch the
hot parts of the machine (compressor, flow pipe
and liquid line). Protect the wires from any
overflow.
15 % 20 % 25 % 30 %
-7 -10 -13
0,987 0,982 0,978 0,974
0,995 0,993 0,991 0,989
1,105 1,184 1,237 1,316
1,028 1,051 1,074 1,100
The safety door interlock automatically prevents electric power being
fed to the unit if the cover panel over the electrical panel is opened.
After opening the front panel of the unit, feed the supply cables through
the appropriate cable clamps in the external panelling and then through
the ducts at the base of the circuit board. The electrical power supplied
by the single-phase or three-phase line, must be taken to the main
isolator switch.
The supply cable must be of the flexible type, with PVC sheathing of no
lighter than H05RN-F: for the section, refer to the table below or the
wiring diagram.
Three phase models (400V-3ph+N-50Hz)
Cables section
Line section
PE section
Remote control
section
The earth conductor must be longer than the other conductors in order
to ensure that in the event of the cable clamping device becoming
slack, it will be the last to come under strain.
II.6.1.1 Remote management using connections set
up by the installer
The connections between board and switch or remote light must be
made with shielded cable consisting of 2 twisted 0.5 mm² wires and the
shielding. The shielding must be connected to the earth screw on the
panel (on one side only). The maximum permitted distance is 30 m.
SCR - Remote ON/OFF control selector.
SEI -Summer/winter selector.
LBG - General lockout light.
Remote ON/OFF enabling (SCR)
-16
Remove the ID8 terminal bridge on the electronic board and connect
the wires coming from the remote control ON/OFF selector (selector to
be installed by the installer).
ATTENTION
Remote summer/winter enablement on EWNHM (SEI)
Connect the wires coming from the remote summer/winter selector on
the ID7 terminal present on the circuit board.
t this point, modify the Rem. Summer/Winter parameter.
ATTENTION
LBG remote control
To remotely control the signal, connect the two lamps according to the
instructions provided in the wiring diagram supplied with the machine
(max. 230 Vac 0.5A AC1).
II.6.1.2 Remote management using accessories
supplied separately
It is possible to remotely control the entire machine by linking a second
keyboard to the one built into the machine (KTR accessory).
To select the remote control system, consult paragraph II.2. The use
and installation of the remote control systems are described in the
Instruction Sheets provided with the same.
36
SECTION II: INSTALLATION AND MAINTENANCE
IMPORTANT!
For electrical connections to the unit and the
accessories, follow the wiring diagrams which are
supplied with them.
115-118
mm² 2.5
mm² 2.5
mm² 1.5
IMPORTANT!
When the unit is switched OFF using the remote
control selector, the letters Scr appear on the on
control panel display on the machine.
Open contact:
Closed contact:
Open contact:
Closed contact:
122-125 230-240
4 6
4 6
1.5 1.5
the unit is OFF
the unit is ON
heating cycle
cooling cycle