CH pump/valve flex to junction box.

[Geo]

My old heating stem has the flexible cables from valve and pump clipped to a wooden board then entering flat trunking via end or a side hole. The trunking contains the flex(s) as far as the Danfoss junction box. I will be adding a futher "zone" with another valve, thermostat and junction box remotely. This will be joined to the first by a 3 core & E cable. What is the accepted method of connecting these flexes to the junction box - should I buy a couple of flex outlet plates (seems OTT) or is a cable clip sufficient as above?

Geo

[Andy Hall]

Plastic junction boxes work quite well.

Have a look at RS Components (rswww.com) part number 365-9267

This is one of a range with other sizes being available.

They are very inexpensive and have 20 and 25mm knockouts into which you can fit cable glands. You can get glands with round holes suitable for flex and oval suitable for cable e.g. 444-2947.

[Geo]

Thanks for the part number pointers Andy - forgot all about RS - will have a rake around their site.

Geo

[Andy Hall]

There are also junction boxes from the likes of Honeywell specifically for CH applications. However, they consist essentially of a surface mount double socket box with a front plate and a chocolate strip inside. The knockouts are at the bottom and are designed just to let in T/E cables - not much use with flex.

BTW, if you do use the Spelsberg boxes, there are some with terminal strips and some without, so be careful and download the PDF data sheet to check. The terminals are good though. They have a leaf spring inside and will comfortably take 3-4 conductors on each side.