immersion heater timer

[bolt the volt]

whats the best timer that wont burn out in under a year (last one i used was a grasslin)

 

[Marvo]

Grasslin are respectable products, I've used them on a good few occasions without problems and I'd rate them as the upper end or the middle of the road products. If it's burned out I'd be looking for another reason other than a faulty timer. Maybe poor terminations or it's overloaded for example.

 

[R G]

I used 2 on a job to control 2 storage heaters , put them in 5 years ago , in constant use and no problems Grasslin that is..

Another one is a Horstman unit with a boost facility , they are in service for years and made specifically for immersion heaters

 

[baldsparkies]

Its not so much the timers, as any faults that develop with regards to the immersion elements themselves.
If the timers contacts are submitted to short circuit or overload conditions whilst in use it will significantly reduce there service life.
Sangamo are very robust, but normally for commercial use.

 

[R G]

Thats why its always best to supply the timer with a sw/ fused spur , never direct , especially if its from a BS3036 board

 

[TJ Anderson]

Thats why its always best to supply the timer with a sw/ fused spur , never direct , especially if its from a BS3036 board

It is a bit of a double edged sword that one as a 3kw immersion runs very close to the limit of the 13A fuse for long periods. I always fit 20A DP switch myself..

 

[baldsparkies]

Thats why its always best to supply the timer with a sw/ fused spur , never direct , especially if its from a BS3036 board

Iv'e seen more than one fused spur with serious overheat damage used this way.
Just shows how punishing, and close to limit, those 3kw immersion elements can be over time.
Often the fuse hasn't blown but the damage is still evident.
Yes they will go bang eventually but the timers internal contacts need to be pretty robust in design to handle it.

 

[R G]

13 amp sw fused spur is whats required with some timers , to avoid the timer being damaged when the element becomes faulty

 

[baldsparkies]

Not disagreeing,
just saying I have seen spurs overheat when subject to overload faults, often as the elements are breaking down.
So although the fused spur will help its not a guarantee that the timer contacts aren't going to get damaged.
Depends what let through current those contacts are subject to before the fuse fails.
As you say a fused spur may help, but those timers do get punished on make and break and overload conditions.
That's why the cheaper poorly made units don't tend to last long.

 

[TJ Anderson]

If you want to make sure it wont happen switch it though a higher rated contactor.

 

[baldsparkies]

If you want to make sure it wont happen switch it though a higher rated contactor.

Now your talking, :icon12:

 

[R G]

Horstman E7 controllers are quite good , fitted many of these in the past , the digital display versions need a fused spur though , I have replaced a few when replacing faulty elements , can't say I have seen many faulty fused spurs though in this situation , it was a company policy to fit a fused spur when installing these when I worked for a contracting side of a DNO....