Contactor explained.

[Anthony5]

In the control box of my swimming pool I have 8 of the pictured contactors installed for each pump or other pool appliance.

The wiring done by a foreign craftsman is a real mess, so I want to redo it myself.

I have figured out which appliance is controlled by which contactor, but don't know the function of each contact on the contactor.

In other words, which contact is the live feed, and which wires are connected to A, L and T connectors

So can someone in layman terms explain what the purpose of each connection on the contactor is. I have a single phase installation.

Thanks in advance.

[RichCor]

Mitsubishi Magnetic Contactor and Magnetic Motor Starter

MITSUBISHI S-N10 MAGNETIC SWITCH

Type Magnetic+Overload Relay : MSO-N10

Rated Continuous Current AC1(A): 20

3-Phase AC motor 380-440V

Current(A) : 9

KW(HP) : 4 (5.5)

Category AC3 AC220-240V

Current (A):11

KW(HP) : 2.5 (3.3)

Auxilary Contacts:1NO

Mitsubishi Electric Australia .pdf page 12 is probably the closest spec wise.

[Anthony5]

Mitsubishi Magnetic Contactor and Magnetic Motor Starter

MITSUBISHI S-N10 MAGNETIC SWITCH

Type Magnetic+Overload Relay : MSO-N10

Rated Continuous Current AC1(A): 20

3-Phase AC motor 380-440V

Current(A) : 9

KW(HP) : 4 (5.5)

Category AC3 AC220-240V

Current (A):11

KW(HP) : 2.5 (3.3)

Auxilary Contacts:1NO

Mitsubishi Electric Australia .pdf page 12 is probably the closest spec wise.

Thanks, but it doesn't answer my question.

I try to find out where the incoming live and neutral go, I suspect it to be Live A2 and Neutral A1

Then I want to find where the wires from the switch that operates the pump or other appliance go. Again I suspect this to be 1/L1 and 3/L2, but I don't want to make mistakes

So what is the function of contacts 2/T1 and 4/T2?

Next if let's say I have a contactor that operates the Chlorinator and which is supposed to auto start the filter pump, which is operated by a similar contactor, when the chlorinator timer switches on or is operated manually.

Which connectors from the chlorinator contactor do I connect with which connectors of the pump contactor?

[Crossy]

It all depends upon the design of the circuit. Incoming live could be on any of the terminals, ditto neutral (if neutral is indeed switched).

The contacts are between L1 and T1, L2 and T2, L3 and T3, L4 and T4, contacts are normally open.

When the coil is energised (220V on A1 - A2) L1 is connected to T1 etc.

In order to work out what you're doing and to modify the operation of the circuit, step 1 is to draw out what you have (I don't suppose you got a drawing?). Trying any other route could result in a bang, a fried chlorinator / pump or a fried Anthony5

Actually Task-A is to define exactly what you want the system to do.

If you are simply wanting to alter how the chorinator / pump timings work you shouldn't need to mess about with anything other than the coil connections and how they link to the timers. start by drawing that part out.

READ THIS - Whilst domestic electrics isn't exactly rocket science I would advise caution. It is apparent you don't really know what you're doing beyond basic lights and power. I really, really would get a man in.

[Anthony5]

It all depends upon the design of the circuit. Incoming live could be on any of the terminals, ditto neutral (if neutral is indeed switched).

The contacts are between L1 and T1, L2 and T2, L3 and T3, L4 and T4, contacts are normally open.

When the coil is energised (220V on A1 - A2) L1 is connected to T1 etc.

In order to work out what you're doing and to modify the operation of the circuit, step 1 is to draw out what you have (I don't suppose you got a drawing?). Trying any other route could result in a bang, a fried chlorinator / pump or a fried Anthony5

Actually Task-A is to define exactly what you want the system to do.

If you are simply wanting to alter how the chorinator / pump timings work you shouldn't need to mess about with anything other than the coil connections and how they link to the timers. start by drawing that part out.

READ THIS - Whilst domestic electrics isn't exactly rocket science I would advise caution. It is apparent you don't really know what you're doing beyond basic lights and power. I really, really would get a man in.

There is actually no external timer involved with the chlorinator, it is built in in the item.

So when the chlorinator starts up contactor A gets activated, I only need to find out which are the right connectors I need to connect to activate contactor B which operates the filter pump and also deactivates it when the chlorinator switches off.

[billphillips]

That looks like a 3 phase motor switch to me. If so, you have 3 live feeds and one neutral. If you don't understand it just by looking ... leave it alone.

[Crossy]

To activate B all you need is to apply 220V to its coil. BUT that's already being fed from somewhere else (what?).

If there is a spare contact on A then you could put that in parallel with whatever is now controlling B so the cholorinator would over-ride the other pump control (is that what you want?).

Have you drawn out what you have yet?

Have you defined exactly what you want to do?

[Anthony5]

To activate B all you need is to apply 220V to its coil. BUT that's already being fed from somewhere else (what?).

If there is a spare contact on A then you could put that in parallel with whatever is now controlling B so the cholorinator would over-ride the other pump control (is that what you want?).

Have you drawn out what you have yet?

Have you defined exactly what you want to do?

This is what I found.

Lets call chlorinator contactor A and filter pump contactor B.

In deactivated state there is no current on any connection of contactor A.

A2 and A1 have a single wire connected and L1 and L2 are bridged.

T1 has a wire connected that goes to the manual switch of the filterpump, while T2 has a wire going to the control light of the chlorinator on the control box.

When the chlorinator is switched ON A2 from contactor A becomes live, and the magnetic contacts pull in, and L1/L2 and T1/T2 become live.

When I remove the bridge between L1 and L2 there will be no current on any of the magnetic contacts when activated, and of course the control light will also not work.

On contactor B ( filter pump) however in deactivated state there is permanent current on L1 only, and no current on A2 or any other connector.

When I manually switch on the filter pump, there will be current on L1 - T1 and A2.

I have now bridged A2 from contactor A with A2 from contactor B, and so the pump gets activated when the chlorinator switches on.

I hope this helps to understand my system.

[Crossy]

I have now bridged A2 from contactor A with A2 from contactor B, and so the pump gets activated when the chlorinator switches on.

You do realise that by doing this you now activate the chlorinator when you switch on the manual pump control.

Actually, you will feed 220V back into the chlorinator output that controls the contactor. Dependant upon what's inside the chlorinator that could fry the works!!!!

Much better would be to use the spare contact on A (as I noted earlier). Just place it in parallel with the manual pump switch and the pump will start when the chlorinator contactor pulls in.

[Anthony5]

I have now bridged A2 from contactor A with A2 from contactor B, and so the pump gets activated when the chlorinator switches on.

You do realise that by doing this you now activate the chlorinator when you switch on the manual pump control.

Actually, you will feed 220V back into the chlorinator output that controls the contactor. Dependant upon what's inside the chlorinator that could fry the works!!!!

Much better would be to use the spare contact on A (as I noted earlier). Just place it in parallel with the manual pump switch and the pump will start when the chlorinator contactor pulls in.

With spare contact do you mean T3?

Because L1 and L2 are bridged, and T1 goes to the pump switch and T2 to the chlorinator control light.

Where does actually the current on L1 and L2 come from when bridged, because when not bridged there isn't current on any of the L or T contacts while the magnetic contact is pulled in?

[Crossy]

If you have no wire on L3 or T3 you can use the contact (switch) between them to control the pump contactor. No danger of feeding back into the chlorinator.

I'm not sure why there is a link L1-L2 (is there nothing else on those terminals?), it seems that for some reason the "designer" has used 2 contacts in series, no idea why.

In order to know what's really going on we need a diagram, that means tracing every wire and drawing out what you have.

Without that we (and you) are really just guessing.

[Anthony5]

If you have no wire on L3 or T3 you can use the contact (switch) between them to control the pump contactor. No danger of feeding back into the chlorinator.

I'm not sure why there is a link L1-L2 (is there nothing else on those terminals?), it seems that for some reason the "designer" has used 2 contacts in series, no idea why.

In order to know what's really going on we need a diagram, that means tracing every wire and drawing out what you have.

Without that we (and you) are really just guessing.

I guess I figured it out.

As I said earlier ALL contactors in the control box have permanent current on L1 in deactivated position.

From the chlorinator contactor (A) contact T1 is wired to a contact on the manual switch of the filter pump, which is a auto/off/on switch, while T2 is wired to one side of the chlorinator control lamp on the control box.

I have now removed the bridge between contactor A and contactor B ( filter pump).

I have bridged permanent current from a L1 contact on a nearby contactor to the L1 contact on contactor A, and bridged L1 and L2.

When I now activated the chlorinator the pump starts running, probably because T1 feeds current to the pump switch, and the control lamp lights up because that one gets live feed from T2. When I set the pump switch to OFF position, the pump will not start when I activate the chlorinator.

I'm sure this gives you some insight on the design from the installer.

So, however the issue is solved now, I consider it not optimal. Because when I forget to set the pump switch to AUTO the pump will not start when the chlorinator timer gets activated.

There is of course a flow protection in the chlorinator, but I consider it not optimal.

What I consider is to disconnect the wire between T1 and the pump switch (or just leave the wire in connected), but additional wire bridge T1 with contact A2 of contactor B. That would switch on the pump whenever the chlorinator is activated, regardless of which position the pump switch is in.

Is this safe to do?

[Anthony5]

Now I start wondering why every contactor has permanent live feed to L1.

Each contactor has only a single wire connected to L1, and probably they are all bridged with each other, that provides permanent current.

Wouldn't it be better if on each contactor A2 was bridged with the L1 contact so that the contact only gets current when the it is switched on, instead of feeding permanent live to L1?

[Crossy]

I'm sorry Anthony, you really are demonstrating your lack of knowledge.

I would stop NOW! There is too much risk of your frying something, or worse, this is all 220V circuitry, it can and will kill!

Do NOT link A2 to anything, you WILL fry whatever is driving it (that will totally negate the purpose of the contactor).

Just leave it as it was and bear with the quirks.

If you want to trace out what you had (before any changes), make a sketch and post it here along with what you are trying to achieve, I and others will be more than happy to assist. But as of now, I'm not going to make any further comments, it's just too risky.

[RichCor]

Anthony,

I suggest you research how chlorination timer/trigger circuits work.

You'll find that logic control circuits (even if they are 220v) are separated from device load circuits. A timer/trigger device can handle powering a magnetic relay (contactor) but can't directly handle the current draw of a pool pump.

If all you are trying to do is prevent the chlorinator from receiving power if there is no water flow, then think about adding a water flow reed switch on the logic control circuit, so that the chlorinator only receives power if water is actually flowing.

As Crossy suggested, make a drawing of the circuit design that's currently in place. Include the timer/trigger, the connecting wires to the contactors, any jumper/bridges, the pool pump, the chlorinator, and where the external power comes in for each. Which paths are control logic, which paths handle direct current?

And get a knowledgeable pool electrician. Water and electrical are in play here. Someone who understands control and isolation needs to be doing the design and work.

[IMHO]

There is of course a flow protection in the chlorinator, but I consider it not optimal.

Why not just power your chlorinator from the same "feed" as your main pump? If the chlorinator has it's own timer, either defeat it or manipulate the time so it's "always on". Then all you need is a single timer on your main pump. Done.

[Anthony5]

I'm sorry Anthony, you really are demonstrating your lack of knowledge.

I would stop NOW! There is too much risk of your frying something, or worse, this is all 220V circuitry, it can and will kill!

Do NOT link A2 to anything, you WILL fry whatever is driving it (that will totally negate the purpose of the contactor).

Just leave it as it was and bear with the quirks.

If you want to trace out what you had (before any changes), make a sketch and post it here along with what you are trying to achieve, I and others will be more than happy to assist. But as of now, I'm not going to make any further comments, it's just too risky.

Crossy I understand your concern and appreciate your help, but I think you misunderstood my last post.

I have no intention to feed live to A2. I know A2 from the every contactor gets a live feed from the switch on the control box or remote control, and activates the magnetic contact.

In the case of the chlorinator, T1 provides live to the switch of the pump, and when this switch is in auto position it bridges the live to A2 from the pump contactor. When the switch is in the off position it doesn't bridge the live.

As I said the L1 contact on each contactor in the box has now a permanent live feed, for which I don't see the purpose, because the magnetic contact only gets activated when A2 gets live feed. So why has there to be permanent live feed on that L1 contact? There are no other wires connected to that contact.

So my intention was to disconnect the permanent live feed from the L1 contact on each contactor, and let A2 provide the live feed to L1.

Is there anything wrong with that?

I will try to make a sketch, but that will take days.

To give you an idea. If you look at the telephone wire spaghetti on the power poles in Thailand, that is a neat job compared with what my farang electrician produced in the control box of my pool house.

[Anthony5]

There is of course a flow protection in the chlorinator, but I consider it not optimal.

Why not just power your chlorinator from the same "feed" as your main pump? If the chlorinator has it's own timer, either defeat it or manipulate the time so it's "always on". Then all you need is a single timer on your main pump. Done.

Why would I install an external timer if there is a timer already in the Chlorinator?

I want to be able to operate the pump manually without activating the chlorinator.

In the past it has happened that I left the switch from the pump in the off position, so when the chlorinator switched there was no flow and it auto switched off when the water level in the cell get low, but I'm sure it isn't favorable for the life of the cell.

With connecting T1 from the chlorinator with A2 from the filter pump, I only bypass the off position of the manual switch.

[bankruatsteve]

I will try to make a sketch, but that will take days.

I doubt you will try and it would take days because you just don't know how to do it. Why do you keep asking for advice, ignore it, and then come up with your own (wrong) solution?

[Don Mega]

I will try to make a sketch, but that will take days.

I doubt you will try and it would take days because you just don't know how to do it. Why do you keep asking for advice, ignore it, and then come up with your own (wrong) solution?

Thats a bit harsh, he aint dead yet so all is good.

[Anthony5]

I will try to make a sketch, but that will take days.

I doubt you will try and it would take days because you just don't know how to do it. Why do you keep asking for advice, ignore it, and then come up with your own (wrong) solution?

Constructive advice is always welcomed, though I feel that your comment didn't belong in that category.

I didn't ignore any advice, I only asked what is wrong with letting the A2 contact provide the live feed for contact L1, instead of have an external live feed on that contact, and so far nobody has answered my question.

I also don't understand what is wrong with having a wire from the T1 contact from the chlorinator connected to the A2 contact of the filter pump, because the A2 contact is directly wired to the manual auto/off/on switch from the pump, and has either live feed already or the switch is open ( off position). So what can be wrong in that connection.

Your constructive advice is welcome, or do you suggest I hire a Thai sparky who probably, judging from numerous threads on this forum, has less knowledge about electric than me?

[bankruatsteve]

From the getgo you have been asked to diagram what you currently have and, if you can, describe what you want with reference to that. My comment was not intended to be constructive - just to suggest that you follow the advice instead of coming up with your own. And yes, a Thai sparky can probably sort you out.

[billphillips]

I think this electro-magnetic switch is being used as a relay. No problems with that .... But without the manufacturers routing diagram, it's just a guessing game.

[RichCor]

I didn't ignore any advice, I only asked what is wrong with letting the A2 contact provide the live feed for contact L1, instead of have an external live feed on that contact, and so far nobody has answered my question.

I also don't understand what is wrong with having a wire from the T1 contact from the chlorinator connected to the A2 contact of the filter pump, because the A2 contact is directly wired to the manual auto/off/on switch from the pump, and has either live feed already or the switch is open ( off position). So what can be wrong in that connection.

If my previous post wasn't enough to give a good example (for letting A2 provide live feed for L1), let me do that now.

If power to A2 is being driven by a logic control circuits then any additional load you place on it will force the current to be drawn through the logic control circuit ... potentially leading to not so good things.

The whole idea of using a 'Contactor' is to provide a remotely controlled switch. So now a low current IC Chip can control the off/on state of high-current-start water pump. The power is already at the pump, but is 'looped' through the 'Contactor' to provide off/on state control for the pump switched to the 'auto' position.

On to your second question. Yes, one of the Tn contact terminals can be connected to A2 of another Contactor to remotely control the off/on state of other devices --- but not sure why you would want to do this, it seems odd unless there is a second Logic State in play. Otherwise (if the original circuit powering the first Contactor can also handle the load of an additional Contactor) you'd just bridge/jump the A1 & A2 relay engage from Contactor 1 to the additional Contactor.

But here's the issue of of using Ln to drive the relay of a second Contactor; (1) It still needs an independent power going into Ln to be present on Tn to drive the additional A2 Contactor relay; (2) the A2 Contactor is then reliant on power being supplied to the Ln contact of the first Contactor to operate (a potential logic breakdown).

So, a question here --

You said you want to run the Pump without the Chlorinator running.

The Pump has an AUTO/OFF/ON switch. I would have assumed that OFF is no power, AUTO looped through the remote Contactor, and ON directly applies power to the pump. This isn't the case?

[Anthony5]

So, a question here --

You said you want to run the Pump without the Chlorinator running.

The Pump has an AUTO/OFF/ON switch. I would have assumed that OFF is no power, AUTO looped through the remote Contactor, and ON directly applies power to the pump. This isn't the case?

The system is up and running, without the T1 ( chlorinator)to A2 ( pump) bypass.

I probably wasn't clear in my explanation.

I can run the pump alone when I turn the switch to the ON position. But what I wanted is that when the switch is in the OFF position, that the pump also runs when the chlorinator timer switches on.

In the past it has happened that I left the switch in the OFF position, and when I came home the chlorinator had shut down because there was no flow. Of course the chlorinator only detects that there is no flow as soon as the cell is almost completely dry, so I guess some damage is done anyway.

Thanks for the help

[RichCor]

So, a question here --

You said you want to run the Pump without the Chlorinator running.

The Pump has an AUTO/OFF/ON switch. I would have assumed that OFF is no power, AUTO looped through the remote Contactor, and ON directly applies power to the pump. This isn't the case?

<snip>

I can run the pump alone when I turn the switch to the ON position. But what I wanted is that when the switch is in the OFF position, that the pump also runs when the chlorinator timer switches on.

In the past it has happened that I left the switch in the OFF position, and when I came home the chlorinator had shut down because there was no flow. Of course the chlorinator only detects that there is no flow as soon as the cell is almost completely dry, so I guess some damage is done anyway.

I would have thought that was what the AUTO position was for ... to allow other devices the opportunity to engage the pump when necessary.

Are you saying the pump switch doesn't have an AUTO position, or the AUTO position is currently doing something else?

[Anthony5]

So, a question here --

You said you want to run the Pump without the Chlorinator running.

The Pump has an AUTO/OFF/ON switch. I would have assumed that OFF is no power, AUTO looped through the remote Contactor, and ON directly applies power to the pump. This isn't the case?

<snip>

I can run the pump alone when I turn the switch to the ON position. But what I wanted is that when the switch is in the OFF position, that the pump also runs when the chlorinator timer switches on.

In the past it has happened that I left the switch in the OFF position, and when I came home the chlorinator had shut down because there was no flow. Of course the chlorinator only detects that there is no flow as soon as the cell is almost completely dry, so I guess some damage is done anyway.

I would have thought that was what the AUTO position was for ... to allow other devices the opportunity to engage the pump when necessary.

Are you saying the pump switch doesn't have an AUTO position, or the AUTO position is currently doing something else?

When the switch is in AUTO the pump get engaged when the chlorinator switches on.

When the switch is in the OFF position, the chlorinator still can switch on, but the pump will not be engaged.

I want to prevent this in case I make the error to leave the switch in the OFF position.

[RichCor]

Then I'd introduce a flow reed switch/sensor.

Similar control logic of how an instant-on water heater functions:

Power Available

Power On
Reed Switch sensor activated by water flow

Bi-metal temperature sensor in tolerance

Activate TRIAC to energize heater coils

if reed switch water flow drops, cut power

if bi-metalic goes hot, cut power

In your case you have a timer/trigger circuit that runs 24/7 and has an activation cycle that you want to interrupt when a certain condition isn't met.

The logic circuit needs to sense this condition, then either prevent or allow power to flow.

[Litlos]

Not sure if has been covered already, but terminals 13/14 are auxiliary contacts only and not main load carrying. It looks like the auxiliary contact rating is 5amp whereas the main contact is 20amps. The auxiliary contact is normally used to provide feedback of the contactor status.

Cheers

[Crossy]

When the switch is in AUTO the pump get engaged when the chlorinator switches on.

When the switch is in the OFF position, the chlorinator still can switch on, but the pump will not be engaged.

I want to prevent this in case I make the error to leave the switch in the OFF position.

Now we know what is actually needed

Actually, I would arrange it so the chorinator won't start if the pump is set to 'off' so we still have an 'off' setting.

But to do as you want let's have a look at the switch wiring, just wire it so 'auto' and 'off' are the same.

But we still really need that diagram.

Alternative fix. Put a note on the pump switch - "Do not switch off" (in English and Thai).