Stationary Photoionization Detector SPID2
User Manual
SPID2 - User Manual (en) - 1.11.docx
Analytical Control Instruments GmbH, Volmerstraße 9A, D-12489 BERLIN, Germany, www.aci-berlin.de
Version 1.11
Page 37 of 60
6.9.
Relays
The device contains two alarm relays and one error relay to control other equipment. The two alarm
relays will be activated if the device detects a gas concentration that lies outside the limit values. The
error relay is activated if an ERROR is detected.
Each relay has a set of change over contacts (SPDT-single pole double throw). All relays are normally
energised so that are de-energised and are switched to a fail-safe condition in case of ALARM or
ERROR.
During normal operation, the normally closed [NC] contacts are open. If an ALARM or ERROR is
detected the relay contacts will change as follows:
•
the normally closed contacts [NC] will close
•
the normally open contacts [NO] will open
Relay nominal switching capacity [resistive load]:
ALARM LO
Relay
2 A / 30 V DC
ALARM HI
Relay
2 A / 30 V DC
ERROR
Relay
2 A / 30 V DC
NOTICE
Avoid peak currents higher than the 2 A maximum rating, which may be caused by
inductive or capacitive loads (e.g. rotating beacons or signal horns). To operate such
devices a secondary relay should be used or the peak current should be limited in
another way.
