Section 6: Unit Start-Up; General; Setting The Operating Parameters; Units With Water (Solenoid) Valve And Thermostat - Pfannenberg PWS Series Installations-, Betriebs- Und Service-Handbuch

PWS Series Air/Water Heat Exchangers

SECTION 6: UNIT START-UP

6.1 General

The cooling unit is equipped with an temperature
control system. The temperature of the air pulled in
from the electrical panel enclosure into the cooling
unit is measured by a temperature sensor.
WA R N I N G !
Ambient conditions and temperatures
in the electrical panel must be in accordance
with the values indicated in the cooling unit
information sheet.
WA R N I N G !
Unit must be operated with the cover installed.
Unit can not cool properly when cover
is not in place.

6.2 Setting the Operating Parameters

6.2.1 Units with Water (Solenoid) Valve
and Thermostat
The cooling unit fan runs continuously.
The solenoid valve controls cooling water flow
according to the internal temperature setting in the
switch cabinet.
The desired internal temperature of the switch
cabinet is set using the thermostat. Factory setting is
at 35°C / 95°F. Adjustment range min. 8°C / 46.4°F -
max. 50°C / 122°F.
Electrical panel enclosure internal temperature > the
desired value set using the thermostat
Solenoid valve open Coolant flows.
Electrical panel enclosure internal temperature < the
desired value set using the thermostat .
Solenoid valve shut coolant does not flow.
If door contact is opened then the unit cycles off.
Temperature Monitoring
If the internal temperature of the electrical panel
enclosure deviates more than 10º C from the desired
value set (factory setting 35°C / 95°F) using the
7
thermostat then the zero potential two-way switch is
triggered.
This switch is wired to the terminal strip.
Wiring diagram
(Technical sheet)
(Wiring diagram on device)

6.2.2 Units without Water Valve and Thermostat

The cooling unit fan runs continuously.
The cooling water flow is controlled centralized
water flow control supplied by the customer.
The door contact cycles the unit on / off. The door
contact output notifies of an open door condition.

SECTION 7: MAINTENANCE

Pfannenberg air/water heat exchangers are
maintenance-free.
Use of a water filter is essential if the cooling water
is contaminated. Please refer to the "Water Quality
Notes" section.
Check the condensation water drainage equipment
at regular intervals.

SECTION 8: TROUBLESHOOTING

Condensation water drainage out of the electrical
panel enclosure must be ensured when the device is
installed.
To prevent frost damage the temperature in the
water circuit must not fall below the minimum
permissible water temperature of +1°C anywhere in
the system.
If the device is stored or transported at temperatures
below freezing the water circuit must be completely
emptied using compressed air.