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Majortech or Cbi geyser timer


Tariq
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I used to have a Majortech switching my 3kW geyser element twice a day, and it packed up after a year. Contacts burned out. Not saying your experience will be better or worse, but it is what it is.

I now own a CBI for about a year, so far with no catastrophic malfunction, but the battery backup life on it is unsatisfactory during load-shedding. Constantly throws my time settings out. I also do miss the greater variety of settings on the Majortech, because my daily bathroom routine can differ during the week, especially weekends, which this simple timer doesn't cater for. For a pool pump I'd say the CBI's limited daily settings are perfectly okay. Except if you want to time anything more precisely, because the smallest time increment is rather large. I forget offhand if it was to the nearest 15 minutes of nearest half-hour or whatever. For energy-saving  or for limiting peak inrush demands on your power network, it could be more useful to get a timer that you can set more accurately to the minute.

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5 hours ago, GreenFields said:

the battery backup life on it is unsatisfactory during load-shedding.

I agree battery backup in these timers are very unreliable, I don’t know the major tech timer but the CBI timer should not be left unsupervised when there was load shedding as it will loose it’s time. Unfortunately the internal battery's go flat after about a year and it cannot be replaced you have to buy a new timer.

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On 2020/05/16 at 5:37 PM, GreenFields said:

own a CBI for about a year, so far with no catastrophic malfunction

I had a CBI for a geyser timer. After about two years it started making a ticking sound (about once a second) and not long after that it stopped working. The display still worked but it no longer pulled in the relay properly. Probably cooked a capacitor or something.

13 hours ago, francois said:

There is also this one:

My dad has that one on the farm for a water pump. He's on the second one... the first one failed.

Just about all of them seem to be yearlings... only good for one year 🙂

 

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They are great value but some are difficult to program so check this before buying.

Don't switch your geyser element directly with its contacts. I know it's a pain but not doing this will shorten the life of the unit big time!

Edited by Richard Mackay
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3 hours ago, Richard Mackay said:

They are great value but some are difficult to program so check this before buying.

Don't switch your geyser element directly with its contacts. I know it's a pain but not doing this will shorten the life of the unit big time!

Sure you may have a better solution, but this is exactly how these units are advertised to work. If I quote directly from the packaging of the HellermanTyton jobbie above:

- Max 20A (3500W) resistive load (Geysers)...

- Internal relay contact directly onto load.

So that is how any average joe would install it, by following the manufacturer's instructions.

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2 hours ago, Tariq said:

The geyser at 3 kw “should” be ok,  what about running a 1.1 kw pool pump, wondering about the start up current though

The timer should be ok even for the pool pump, but its contact will eventually fail as it only have a certain lifespan. Every time it switches a load on or off, it makes a spark across that contact and that is what eventually kills the unit, unless the internal battery fail first.

Then if there was to be a dead short across the load side, that is almost a guarantee to blow that contact. This is what happens quite often to day-night switches when some energy saving globes when they fail cause a dead short blowing the day-night switch as well. Thats why its always better to split the control circuit from a power circuit.

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  • 2 weeks later...
On 2020/05/18 at 11:26 AM, Tariq said:

The geyser at 3 kw “should” be ok,  what about running a 1.1 kw pool pump, wondering about the start up current though

   Tariq 

 

I am a bit late to the party but I actually have a Majortech MTD8 switching my 1.1kW pool pump (twice a day, 7 days a week...).... touch wood it has been going for about 4 years now. (inrush on the pump is about 30A at 230V  and running it draws about 6.2A...name plate of the pump indicates 7A).  I find the setting procedure fairly simple - biggest gripe is that the screen can be very difficult to read in bright light.

I also have some majortech plug point timers...they have never switched any thing over 100W and have only seen very intermittent short time use -  one is still going also about 4 years on but another one died after only a few uses (when energised the relay sounds like a cell phone in vibration mode).....

An option that I am looking at but way more expensive is a sonoff that switches a contactor...

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12 hours ago, Tariq said:

Thanks for your Input Introverter, what rail do you have the Majortech installed in, DIN or MINI ( Samite ) rail

Din rail (in one of the many available ready-made pool DBs).

If looking at putting a timer on a samite board you may be able to use some adapter clips (https://www.cashbuildonline.co.za/products/adaptor-clips-sabs-samite)... for what it is worth I decided I will not put any of the consumer timers (majortech/CBI/hellerman) on my 3kW geyser. My uneducated opinion is that with a geyser the sustained high current draw is too close to the design limits and I suspect heat will be the major culprit leading to premature failure of the timer at best and possibly fire risk at worst. (the very high current on the pool pump startup is only a few milliseconds where after it drops quite low.... a 3kW geyser is very near the top limit and will be doing that for minutes (?) at a time).

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