Door Contact Switch - Pfannenberg DTT 6401 Serie Instrucciones De Servicio

ENG
4.6.4

Door contact switch

ATTENTION
Damage to the unit!
Damage to the unit and the controller by applying external voltage to the door contact input.
• Do not apply external voltage to the door contact input.
• The door contact input provides a low voltage (< 20 V, 20 mA) for the door contact switch.
Fitting a door contact switch increases safety and prevents increased condensate formation. The door contact switch switches
off the cooling unit motors (fan, compressor) when the switch cabinet is opened.
The door contact switch must interrupt the connection between the terminals X50:3 and X50:4 when the switch cabinet door is
open.
Connector strip/terminals
X50:3 Door contact
X50:4 Door contact
Tab. 7: Collective fault signal
4.6.4.1 Connecting a door contact switch
Prerequisites
DANGER – Danger to life due to electric shock. Make sure that the unit is voltage-free.
Procedure
1. Connect the door contact switch (S1) according to the connection diagram to the connector strip X50 on the underside of
the unit, see "Electrical circuit diagram – Multi-Controller (MC)", Page 42.
– Use a shielded cable with twisted pairs to avoid interferences. Connect the shield to the terminal for function
ground on one side.
– If no shielded cables are used, make sure that no sources of interference are laid in the immediate vicinity.
Sources of interference are: Power cables and components with increased electromagnetic radiation, these
include, for example, frequency converters or motor drives.
2. Close the switch cabinet, restart the unit and check the function of the door contact switch:
– Open the switch cabinet door when the unit is running, the motors (fan, compressor) must switch off.
The door contact switch is connected.
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Operating Manual | Roof-mounted Cooling Unit | Multi Controller (MC) – 115 V | 086100029c
Voltage
< 20 V
Current load capacity
20 mA
Version
Potential-free door contact
(normally closed)
44/45