outdoor heater circuit with pir....

[uksel]

PS. the DOL means the heaters wont be coming on every 5 minutes when cats go past or there's a bin bag flying around. only when you want them to come on...


Actually, my thoughts wouldn't work - as soon as the PIR drops out, you will be losing the supply to the contactor, meaning you'd have to manually press the DOL start button after every time the PIR resets.


hmmmmmmm

after a little rethink - Loop the L1 feed straight into A2 (or A1 depending which end you connect the neutral), this would turn the heaters on solely with the PIR rendering the push buttons useless

 

[reese646]

Thanks for taking the time, so the DOL would replace the relay/contactor then I'm guessing, like i said this sort of switching is new to me. the two heaters could then have in line switches to control them on/off I'm assuming.......

any ideas on a way round the problem you've mentioned...

 

[reese646]

Re: need advice on relays and circuit

XRAYTEK thanks alot I think were on the same page, what sort of relay/contactor would I need for this set up, as in exactly what and would i get it from a local retailer eg. screwfix/maplins.......

actually scratch that I see you've listed the exact module needed I think that would work nicely

 

[uksel]

perhaps, install a rotary isolator (also to be used as for functional switching) for turning them off altogether if required.

and an option could be to wire the DOL as per the drawing, but loop another supply from the live connector, to connection 13 of the contactor in the DOL, and the existing L1 loop could be placed into connection A2 instead of previous 13. this would mean, if you wanted the heaters on for a long period you could switch them on and off manually, then the heaters could be controlled automatically by the PIR's, but turned off all together if required, or turned on and off manually using the stop start controls of the DOL.

you can buy DOL's with an isolator on them which could be handy for the above. but it's beginning to become a bit of a minefield where someone with a good understanding should be doing this for you.

I also think conduit is a must for you. I also think professional installation is a must here tbh.

 

[wattsup]

Re: need advice on relays and circuit

I'm confused, why not use two x pir's, one for each heater...am i missing something? isolator for each?
or 4-pole contactor interlinked ?

4-pole contactor is energised thru the pir, however two isolators/time delay or whatever to said heaters?

Sorry its late, i don't get the need for relays...It seems very over engineered

The load is on the mains side, not the coil feed...so no, you cannot use a cheap low wattage one. You will need a 16/20amp relay or a 16/20 amp contactor. Both with 230v coils (unless you choose to use transformers for coil feeds)
The relay method is nuts btw. Relays are not normally used for the application you have in mind.

 

[Davey101]

Re: need advice on relays and circuit

I think the contactors were suggested before it was realised that the OP had a PIR suitable for the load (the pir is actually rated at 3kw, which is what his total load is, dont know how reliable the pir will be with this load.).
Relays arent being used, contactors are, just a case of mistaken terminology.

I havent got any experience of using a heavy duty PIR (as far as I remember anyway), if the price is similar, I'd go with the contactor option, you have a bit more flexibility for future heaters etc.

Personaly, I'd use a 2 gang switch, so you can decide which heater you want on.

 

[baldsparkies]

Re: need advice on relays and circuit

Dont forget the pir will need movement once it times out, and from what you say your going to be seated. I agree with the comments regarding over engineering. Would you not be better having a room stat and or a timer instead of the pir ? Forget the relays, as said use a contactor for load switching.
By the way watch the manufacturers load ratings for switching under load. inductive as apposed to resistive loads can fuse the contacts together due to arcing. If you do use a pir, let it drive the contactor coils and let the contactors do the load work. Even though it might say 3kw that pir wont last long if used to switch the loads.

 

[Guest123]

Threads merged as they are one and the same.

 

[Davey101]

lol, this is getting a bit complicated for something pretty simple.

Use a cheap pir if thats the way you want to switch it.
Use a contactor, this will avoid any problems with the load on the pir. A Merlin Gerin 2 or 4 pole 20amp will be perfect.
Use a suitable enclosure so you aren't messing about with wiring between bits of kit.
Use whatever type of manual switch you want.
Make sure of correct current carrying capacities.
Choose the correct type of cable
Make sure its all waterproof.
Make sure the pir is in a suitable position, and isnt affected by the heaters.
RCD it.
Make sure you dont mount the heaters on or near something flamable.
Sparkies need feeding too- get and pay one to do it.
Simples.

Good luck. Dave.

 

[lloyd1980]

Hi have joined here to get some advice as I've an outdoor heater to fit, and am unsure of the best way to do it.

the circuit would be as follows:-

need to know the best way to do it, as there seems to be alot of single cable runs and the only way I've come up with is a bit of a mess

think this makes sense, however like I said would you just use one of the cores in a twin core and earth need all the help I can get....

Appreciate you taking the time to look at this

Alan

I would take a main to the PIR first then from this id take a cable to the 2 gang switch, then from the 2 gang switch run a 3 core to heater 2 and then a twin to heater 1 from heater 2

the main to the PIR will be l+n the twin from PIR to 2 gang will become a switch wire -n
take this switchwire to be your live at the switch and connect to common
link the commons with a small peice of brown conductor,
take 3 core, 2 cores will be switchwires and one will be the neutral
use brown as switchwire for say heater 1
black as switchwire for heater 2
grey as neutral and connect to the n of the twin coming from the pir

at heater 1 take the brown into the L terminal and N in the N terminal
connect twin onto the 3 core so brown of twin connected to black of 3 core (switchwire for heater 2)
and neutrals together
and at last heater connect cable as normal

seemples

 

[uksel]

I would take a main to the PIR first then from this id take a cable to the 2 gang switch, then from the 2 gang switch run a 3 core to heater 2 and then a twin to heater 1 from heater 2

the main to the PIR will be l+n the twin from PIR to 2 gang will become a switch wire -n
take this switchwire to be your live at the switch and connect to common
link the commons with a small peice of brown conductor,
take 3 core, 2 cores will be switchwires and one will be the neutral
use brown as switchwire for say heater 1
black as switchwire for heater 2
grey as neutral and connect to the n of the twin coming from the pir

at heater 1 take the brown into the L terminal and N in the N terminal
connect twin onto the 3 core so brown of twin connected to black of 3 core (switchwire for heater 2)
and neutrals together
and at last heater connect cable as normal

seemples

i dont think you've explained that very well

 

[reese646]

lol now I'm starting to get confused as to which is the best way to do this, contactor or not, run through the pir or not.... have come up with this over the weekend, think it looks over enginerred to be honest but it means all the cable runs work, the system can be turned off, the pir is taking no load so I can get a cheap one, and both heaters are independantly useable

think this is a cummulation of the advice I've had but feel free to correct me if this won't work, but can't dee why not

 

[baldsparkies]

Wow, this is all getting very complicated. I can only start from scratch and give you a my thoughts. but it will work.

1st lets refer to the install as having two circuits to wire. Circuit 1 being the control circuit, and circuit 2 being the load circuit.
Ok Circuit 1 control this will feed the pir, with the switch side going to the common of two 1 way switches. The load or L1 side of the switches would feed the coils on 2 x 20A contactors. thats it, hard part done. the pir will operate either or both contactors depending on the switches being off or on.

Now circuit 2 the load circuit. that needs to be a feed to the supply side of each of the contactors with the load side going to each individual heater. Follow iee regs regarding shock and overload protection along with IP ratings and mechanical protection and your there.
Hope this helps

 

[Davey101]

I feel a bit daft replying to this again, but I've started, so I'll finish

Scrap your latest drawing.
The wiring on your previous drawing was spot on.
Baldsparkies advice is good, and will work, its a common way of wiring this type of arrangement.
Some of the other advice less so.
I, personnaly, would not use 2 contactors, mainly due to cost (I've never bought a contactor in my life, as I get them FOC, so I dont know what they cost), the load for each heater is only about 6.5 amps, so a 20 amp light switch should be fine.

Now, look at your 'actual wire runs' drawing. See how many JB's, and 'wire runs' you have?
Now put all the connections inside one big JB, i.e. an enclosure with din rail conectors, and a contactor, its a bit easier.

If it were me, I would wire a '2 way and off switch' into the circuit. This switch, in postion 1 would put a feed onto the PIR, so it works as you want , i.e. automatically. Postion 2 would put a feed onto the switched side of the PIR, so that the heaters are on wether the pir is activated or not, i.e. on all the time. Postion 3 kills both feeds, so the PIR, and heaters are turned off.

Dont include earths or neutrals on your drawings, it just makes things more confusing (they are still much better than I can do on a computer though

 

[baldsparkies]

Davey, I would not want to see the guy rely on the pir for load switching. the 3000w rating is only half the story. the small internal relay contacts will eventually go south with the constant arcing the heater loads will produce. Buy a lower rated cheaper pir, use it on the control side and use the saved cash towards a couple of contactors with 240v coils (There not that pricey)