The most crucial fact to remember when putting up a bathroom extractor fan is that a licensed and certified electrician must perform any electrical work. Since water acts as a deadly electrical conductor, no non-professional should attempt electrical works as part of a DIY project, especially in the bathroom.
Therefore, this article serves as a guide to prepare for the electrician’s arrival rather than a guide to follow during the installation.
Choosing a location for the fan is the first step because its site significantly impacts the kind of fan you can and should install. The 17th Edition wiring regulations state that electrical equipment must not be installed within a certain distance of a bath or shower. According to these rules, every appliance that is horizontally or vertically close to a sink, bathtub, or shower must be either SELV (Safety Extra Low Voltage) (12v) or IP*5 rated (resistant to sprays of water).
There is one important ramification of putting in a SELV fan. To operate on 12v, rather than the standard 240v, a low-voltage fan requires a transformer. This transformer, not the fan, will be drawing power from the mains 240v supply, hence it must be located outside the bathroom zoning system.
The fan’s operation mode is now up to you. The following are some of your choices:
• By using the light switch in the restroom
• Using the included pull cord is an inherent part of the fan’s design.
• Using a pull cord located elsewhere (maybe by the bathroom’s door)
• By a humidity switch that activates the fan at predetermined relative humidity levels.
• If you’d like the fan to remain on for a predetermined time after you’ve shut off other electrical sources (such as the lights), an “overrun timer” can be programmed.
• If you want the fan’s speed to increase or decrease on demand (a “boost” or “trickle” feature), select the appropriate option.
Standard two-core and earth cable, also known as twin and earth, is required if you plan on operating the fan with a light switch, pull cord or other remote control. (6,242 foot, flat, power cable)
You will need the three core and earth, which is not as commonly used but is still easy to find if you have chosen a fan with boost or trickle functionality or a timer. Flat power cable (6243 yds). The supporter will need access to both a switch live’ and a ‘permanent live’ feed.
So, you have chosen the location for the fan and the switch. This reveals the path used by the primary power wire. Your electrician can run the appropriate wire from the fusebox or other power distribution panel to the switch and from there to the fan. While some homeowners may be capable of handling this independently, most electricians prefer to take every aspect of a job from start to finish. This is because a) even the simplest of tasks has the potential for deadly effects if performed incorrectly. I can’t count the number of times I’ve seen a broken cable because someone fastened it to the wall behind some capping in a cable channel without realizing what they were doing. A live nail has made contact with the insulated copper conductor beneath the cable and is ready to deliver a 240-volt shock to anyone who touches it.
However, a straightforward, albeit messy, task may be completed before the electrician arrives. A ‘core cutter’ will allow you to quickly prepare the ducting hole. An extractor fan requires a hole measuring 100 millimeters (about four inches) in diameter for a standard-sized bathroom. On the other hand, six-inch fans are standard in most kitchens and larger bathrooms. The fixture on the back of your lover should fit into a hole that is the same diameter as normal ducting.
You shouldn’t try to do it the old-fashioned way without a core cutter, which involves marking a four-inch hole on the wall, drilling pilot holes around its circumference, then knocking out the hole with a bolster and hammer. This is not only lengthy, laborious work but also yields an awful result, as someone with firsthand experience can attest. You will have sections of missing wall that aren’t hidden by the front grille of the fan, and the hole itself won’t be perfectly smooth or level, letting in drafts from the outside.
All electrical connections must have earth leakage protection installed per the 17th edition standards. An RCBO or RCD can be used for this purpose. If you connect the fan to the light switch, the circuit is probably already RCD-protected. However, especially with older homes, there is no assurance that this is the case. Remember that your electrician may need to replace your entire fuse board to accommodate the RCBO or RCD, which might significantly increase the project’s cost. If that’s the case, finding a reliable electrical wholesaler or online electrical merchant to purchase the parts from (according to his specification) would help you save money.
If you decide to publish this post, the author would appreciate keeping all backlinks to Extractor Fan World intact.