Efc21 Standard Installation - Cisco 3905 User Manual

6 • UK

2.3 EFC21 standard installation

Description
The diagram shows how a separate solenoid valve (SMG) must be connected to the EFC21. The
solenoid valve is part of the separate fail-safe system and will cut off the gas supply in the case of
insufficient system chimney draught (controlled by the fan pressure switch).
• Connect the earths of the mains supply, chimney fan and solenoidvalve
together (SMG).
• Connect the chimney fan and pressure switch to terminals 1–5.
• Connect the SMG to terminals 6–7.
• 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. 6
Unit
Fig. 7
Chimney fan with pressure switch (PDS)
Isolation switch
EFC21
SMG (solenoid valve)
3001736-EFC21-EFC25-UK
Mains
Gas