Efc21 Installation With External On/Off - Cisco 3905 User Manual

3001736-EFC21-EFC25-UK

2.4 EFC21 installation with external ON/OFF

Description
Example showing how an external ON/OFF switch can be connected to a standard installation. Al-
lows the system to be switched ON/OFF by the external switch or by the controller.
• Connect the mains earth to the earth terminal of the chimney fan and to the solenoid valve
together(SMG).
• Connect the chimney fan and pressure switch to terminals 1–5.
• Connect the SMG to terminals 6–7.
• Connect the external ON/OFF switch (potential free) to terminals 8–9.
• Connect the optional Air inlet monitoring to terminals 10–11. If this monitoring is not manda-
tory then a jumper must be fitted across terminals 10–11.
• Connect mains supply to terminals marked "Supply".
Wiring diagram
Fig. 8
Unit
Fig. 9
Chimney fan with pressure switch (PDS)
Isolation switch
External ON / OFF
SMG (solenoid valve)
EFC21
Mains
Gas
UK 7