Timer switch question

These things are commonly available...this link is for UK..but a search for 'bathroom fan over-run timer' should produce results relevant to your country...

Del

Adding a simple industrial, pin based, timer would be your most ecconomical route. Pin based timers have been in use as a deley in operations on machines for years. The wiring is simply routed back into the timer to feed the fan. Once the switch is turned off, the timer is released and automatically resets. These timers have either a dial on the head or an array of pin switches to very the settings.

Maximo

Thank you gentlemen I found a switch.

Make sure that it is "heavy-duty" rated. Pun intended.

And intrinsically safe.

In the UK, bathroom fans are supplied with a control unit that has four terminals. Live, neutral and earth are the normal three. The fourth is connected to the swithed-live that is connected downstream of the light switch. When the light is turned on, the control unit energised the fan. When the light turns off the switched-live de-energises, and the circuit maintains the fan from the other three terminals until its on-board timer expires. The timer is adjustable.

For further research, perhaps it might be a good idea to visit a major home improvement centre locally, and look for bathroom fans and timers?

Forced extraction for bathrooms and other often-wet areas has become a requirement for new-build homes and new extensions under the latest set of Building Regulations in the UK. The reason for the requirement is so as to minimise the risk of deterioration to both building and occupants by providing a facility that enables the avoidance of condensation within the building. Building designers will call for these items on submitted drawings prior to Building Regulations Approval, and Buildings Inspectors will look for these items as part of their inspection routines during the build. Failure to install will delay the production of the Completion Certificate, the absence of which will certainly inhibit the ability of the home-owner to sell the property.

It is called a "delay off relay" google it.

Wangito.

Thanks once again!