Swimming Pool Starter Help!

[dlt27]

Hi and thanks in advance.
I have been called to a job to look at a faulty starter for a swimming pool.
The starter apparently has never worked and swimming company has agreed to pay for it to be fixed ( there electrician has had 2 goes already).
The starter is supposed to be wired so that if there is a power cut the pump automatically restarts, also it is controlled by a 240v timer which also turns on 2 uv lights.
The starter at the moment never turns off by the timer and the reason for this I noticed straight away is that starter is a 415coil being controlled by a 240v timer.
The main trouble I've got is does anybody know if there is a starter with 240v coil and n/c contractor so after power cut it automatically restarts. Existing starter is Schneider LM35P714.Thanks again.

 

[HandySparks]

Just to clarify, what's the supply to this pool equipment? Single or three phase?

 

[Pete999]

Just to clarify, what's the supply to this pool equipment? Single or three phase?

Just to clarify, what's the supply to this pool equipment? Single or three phase?

I would imagine it's 3 phase as his initial post mentioned the coil voltage as 415v that's not to say the pump is though.

 

[dlt27]

Sorry , just got in from work..
I live in Worcestershire for anybody who would like too know.
I installed all the supplies for pool last September ready for the pool guys (see 1st picture). I got called back last week to see if I could sort why circulating pump isn't turning off as pool electricians had had no success.
They have wired as in my crude diagram.
Also I have downloaded picture of there starter (3 phase in and out L from time clock to A2 and N from timeclock to 96 on overload).
What I believe they want to happen is for pump and uv lights to go of at night, however if there is a power cut they want it all to automatically restart. Thanks

 

[dlt27]

Pool plant room.

 

[dlt27]

Crude drawing

 

[dlt27]

Starter 415v coil.

 

[ruston]

Sounds bizarre as the circulating pump should be running to keep the water clean and maybe off at night only.

It does not sound like a good set up at all . The poor old filtration system will be on catch up all the time . The bacteria will be having a field day with the UV off.

 

[dlt27]

Sorry L into A1 not A2...

 

[westward10]

The time clock looks like it has been set but stays on? Is the clock switch on Auto.

 

[dlt27]

The time clock switches uv lights on and off ok when in auto.

 

[dlt27]

I don't understand how pump is always running as I thought DOL starters were Normally open contactors!
Would it be possible to get a normally closed contactor with thermal overload and mount in an enclosure?

 

[westward10]

Sounds like the clock is not controlling the motor starter.

 

[marconi]

http://www.greenbrook.co.uk/eshop/files/files/T100A-C-Ins-LOW.pdf

The problem is that you/someone has supplied and fitted a timer which does not have volt-free contacts. The timer in use - see link above - supplies a time switched live and a neutral both derived from the lower right FCU. From the image you supplied you can see an anomaly - even with this RH FCU switched off the timer neon is lit. What this indicates is a second problem with the wiring of the starter/time switch combination, namely that one of the three phases is being back-fed into the output of the timer - the timer lamp lights because it has this phase and a neutral across it.

The starter in question has a 415V ac coil. It must be supplied from two of the three phases at the input to the starter. The starter is required to operate in 'non-latching mode' - see page 7 of 8 of:

http://download.schneider-electric.com/files?p_Doc_Ref=1549518_01A55&p_EnDocType=Instruction sheet&p_File_Name=1549518_01A55-11.pdf

As you correctly say the appropriate connections are to A1 and 96 so that the start and stop push switches are out of circuit. What you have to arrange is for a 415V supply tapped of the input to the starter to pass through some Normally Open volt-free contacts controlled by a 240V timer. With such a scheme the starter will only close during the programmed On periods or if the timer is switched to Override (the I position). You need a separately switched 240V from the timer for the UV lamps. The type of immersion heater timer currently installed and those of similar manufacturers don't normally have a second set of Volt Free NO contacts. A quick search of such timers by me has been fruitless.

So, what you need is a 240V relay controlling a pair of volt-free NO contacts. The output of the current immersion heater timer can then control this relay and the UV lamps. The relay's NO contacts switch the starters coil.

You need to purchase:

230v AC 8 Pin Relay 2 Pole - https://www.tlc-direct.co.uk/Products/SR501.html

8 Pin Octal Base Din Type - https://www.tlc-direct.co.uk/Products/SR511.html

and a suitable box to put it in and a glands for the two cables to it - one for the coil and the other for the NO contacts.

And ' and after a power-cut the pool pump motor restarts' is I believe inaccurate. The functionality required is that after a power cut the system must not require resetting and restarting. This achieved by bypassing the Start Push as is alrady in place. The pool pump will restart after a power cut with out the need for resetting and restarting and if the timer is in an ON period. However, you need to clarify whether the timer clock is required to be maintained during a power cut so that it continues to use the true time. In which case you need to swap the current electro-mechanical timer for an electronic one such as:

24 Hour / 7 Day GP / Immersion Heater Timeswitch - Electronic - https://www.tlc-direct.co.uk/Products/SMNTT03.html

 

[marconi]

I exceeded the blasted 20 minute rule - at the end of the first para above please read:

that one of the three phases is being back-fed into the output of the timer - the timer lamp lights because it has this phase and a weak neutral ( - because the FCU is off it is a capacitative path to N through which a low current albeit enough to illuminate the neon) across it. The starter coil remains energised because it has a phase on one side and another phase or neutral via the UV lamps (when the FCU is on) - it has voltage supply whatever the state of timers contacts be they closed or open because the timer contacts are not volt-free.

This is what I reckon the problem to be.

 

[Wilko]

Awesome !
I'm still digesting this along with breakfast. Out of interest, the 2nd timer has a variant NTT04 that has volt free contacts, but it sounds like 2 poles are needed anyway. So we are back to the relay.