Wireless Electrical Relay

nailer8

Anyone ever hear of a wireless electrical relay?

I am upgrading my heating controls to have 3 zones.
2 Rad zones and 1 HW zone. As this is an upgrade i am going wireless to avoid running cables. I already had a 220v supply in the hot press and was able to use wireless programmable thermostats to control the motorised valves.

My problem is in order to do the job right i need to have the motorised valves sending a signal to the boiler to bring it in when ever they are open.
There is no hope to run a cable to the boiler so what i want is some sort of wireless relay.

i.e. when the N/O volt free contacts in the valve are closed the relay transmitter picks this up sends a signal to a receiver relay (at the boiler) which closes it's volt free contacts (engaging the boiler).

Anyone ever hear of such a thing?
Seems simple enough (similar technology in fact to the wireless thermostats).
Cant seem to find anything on-line though.

M cebee

haven't used any wireless stuff

but i'm sure this is available

DublinDilbert

I would definitely run a cable. There's always other ways they can be run.

Wireless stuff is great in theory but will never work 100% of the time, your never guaranteed to have a channel. Some things need to be wireless, eg a mobile phone, but fixed stuff is better off wired.

Bruthal

DublinDilbert wrote: »

I would definitely run a cable. There's always other ways they can be run.

Wireless stuff is great in theory but will never work 100% of the time, your never guaranteed to have a channel. Some things need to be wireless, eg a mobile phone, but fixed stuff is better off wired.

yea when it comes to a heating system id agree, especially on the link between the motorised valves and the boiler control loop.

nailer8

I agree 100% that wired is always better than wireless but i am not willing to start tearing apart my duplex apartment just to run that cable. If i had a house with an attic etc i am sure i would find a way but i don't think the guy upstairs would be too happy if i ran the cable across his floor ;-)

Also central heating isn't exactly mission critical (although the wife might disagree) worst thing that could happen is a is a cold house.

I found this online last night but cant seem to find them anywhere in Europe.
LevNet Transmitter and LevNet Relay.
Seems like what i need.

M cebee

i'd agree with you

no biggie if boiler doesn't fire

sure if wireless stats are used what's the big deal about wireless call for heat -assuming it works


fit an isolator at boiler

DublinDilbert

nailer8 wrote: »

If i had a house with an attic etc i am sure i would find a way but i don't think the guy upstairs would be too happy if i ran the cable across his floor ;-)

We were just trying to warn you of the pit falls. I don't think you would be too happy if your heating won't work when the guy up stairs turns on his crappy video sender!

Is there any spare alarm or comms wiring that you could piggy back onto?

This will probably do what you need to, but is expensive:-
http://www.rfsolutions.co.uk/acatalog/200_Series_Unibidirectional.html

Bruthal

M cebee wrote: »

i'd agree with you

no biggie if boiler doesn't fire

sure if wireless stats are used what's the big deal about wireless call for heat -assuming it works


fit an isolator at boiler

At least if the wireless stat brings on the heating through interference the motor valves will have to open to bring on boiler, but if the wireless contacts close from an outside radio source, the motor valves will still be closed when the boiler comes on.

Probably is no big problem though.

DublinDilbert
This will probably do what you need to, but is expensive:-
http://www.rfsolutions.co.uk/acatalo...rectional.html

They look interesting, i was looking at x10 stuff myself, they dont seem to have a transmitter operated from input contacts though, like your linked ones do.

M cebee

robbie7730 wrote: »

At least if the wireless stat brings on the heating through interference the motor valves will have to open to bring on boiler, but if the wireless contacts close from an outside radio source, the motor valves will still be closed when the boiler comes on.

Probably is no big problem though.


They look interesting, i was looking at x10 stuff myself, they dont seem to have a transmitter operated from input contacts though, like your linked ones do.

is reliablity/interference a major issue with this rf stuff now? i doubt it

Bruthal

M cebee wrote: »

is reliablity/interference a major issue with this rf stuff now? i doubt it

Probably not, but any radio frequency stuff is open to interference, the radios i use for the RC flyin are 2.4ghz and i have not seen one incidence of interference on them in 3 years im using that band now even close to wifi systems, before that i was using was 35mhz which did have a bit. The wireless DublinDilbert linked uses the 433mhz band, long range 2 way radios use that band also, and long range RC radios now use it although they frequency hop constantly to avoid conflicts.

So it probably would be reliable enough to do the boiler contacts that way. All we were saying is hard wiring is better.

M cebee

yes

DublinDilbert

M cebee wrote: »

is reliablity/interference a major issue with this rf stuff now? i doubt it

Does your mobile phone work 100% of the time? Does your wifi always work on your laptop? They both work most of the time, but no one can guarantee you they'll work all the time.

These devices use ISM unlicensed bands your competing with all other devices within your vicinity for the available RF channels. If there's a stronger transmitter your signal will be lost.

Even if you have a licensed band, there's no guarantee that it won't be blocked either.

Modern systems do use frequency hopping to try find another channel, but one cheap video sender can wipe out all available channel.

Bruthal

DublinDilbert wrote: »

Modern systems do use frequency hopping to try find another channel, but one cheap video sender can wipe out all available channel.

Yes they can, although on the RC aircraft they are far enough from the cheap video senders to select the transmission from the radios so they work very well, it is a bit more tricky in the RF congestion of a housing estate alright.

The frequency hopping does`t look for another channel on the RC long range system, they constantly change every few miliseconds as part of their design regardless if other radios are in the area or not.

I took on that tractor for RC conversion as a matter of interest D.Dilbert.

SparKing

http://www.uk-plumbing.com/sunvic-radio-controlled-room-thermostat-tlxrfp-p-42332.html?zenid=3354dbb776f94e864efb3b6031342a45
I've used these, found them good. Bit of a time delay, less than 30 seconds mind. Used to have them cheap in B&Q from time to time

M cebee

SparKing wrote: »

http://www.uk-plumbing.com/sunvic-radio-controlled-room-thermostat-tlxrfp-p-42332.html?zenid=3354dbb776f94e864efb3b6031342a45
I've used these, found them good. Bit of a time delay, less than 30 seconds mind. Used to have them cheap in B&Q from time to time

he's already done that:)

nailer8

Thanks for all the help everyone.

BTW I haven't actually bought the wireless programmable thermostats yet.

I may have found another solution although probably no cheaper than the RFsolutions proposal earlier.

If i went with the Danfoss randall wireless stats they can work with multiple receivers. The following setup would apparently work but also is pricey.


2 x TP7000Si-RF Wireless Programmable Room thermostats.
1 x WP75-RF Wireless Programmable Tank Thermostat.
2 x RX3 3-Channel Receivers (one for the motorised valves and one for the boiler)

The only danger then would be if there was interference as suggested above you could have a situation where the boiler was engaged and all the motorised valves were closed.
I assume this would not be a safe situation or would the boiler cut out once it got hot anyway?
One option would be to fit an automatic bypass valve but that means draining the system again :mad:

DublinDilbert

robbie7730 wrote: »

I took on that tractor for RC conversion as a matter of interest D.Dilbert.

Oh did ya? very good.

PM me if you need any help or parts.

Bruthal

DublinDilbert wrote: »

Oh did ya? very good.

PM me if you need any help or parts.

Yea i have the forward-reverse and 2 speeds all workin with micro switches operated by the RC servo`s. The micro switches in turn operate car relays. The 2 speed is done by switching the 2 motors on back wheels from series to parallel, and the forward reverse is just the swapping of + and -, all using 5 spst 40A car relays,

Just waiting on the steering servo now. There`s a video of it in the models section (remote control question) if you want to have a look. I put it up so the OP could see the progress. Have a look at the circuit which is on the thread, i am thinking of using diodes for the back EMF of the relays which are causing the servos to jump slightly when the car relays de-energise so maybe you can look and see what you think.
They dont jump when far enough from the relays but the diodes might be a good idea anyway.

Anyway back to the topic:)

slavetothegrind

give nigel a ring in industrial controls, red cow industrial estate dublin

think i saw a relay in there with ariel attached! he may know of options for you if he doesn't have any.

Industrial Controls Ltd
Unit 5 Red Cow Interchange Ind Est Ballymount 22 Co. Dublin

* (01)4037275

M cebee

nailer8 wrote: »

Thanks for all the help everyone.

BTW I haven't actually bought the wireless programmable thermostats yet.

I may have found another solution although probably no cheaper than the RFsolutions proposal earlier.

If i went with the Danfoss randall wireless stats they can work with multiple receivers. The following setup would apparently work but also is pricey.


2 x TP7000Si-RF Wireless Programmable Room thermostats.
1 x WP75-RF Wireless Programmable Tank Thermostat.
2 x RX3 3-Channel Receivers (one for the motorised valves and one for the boiler)

The only danger then would be if there was interference as suggested above you could have a situation where the boiler was engaged and all the motorised valves were closed.
I assume this would not be a safe situation or would the boiler cut out once it got hot anyway?
One option would be to fit an automatic bypass valve but that means draining the system again :mad:

safer to get MV's to open before firing boiler-for sure

no biggie if boiler didn't fire over wireless then

although ya'd prob need ABV for pump-over-run or frost-protection (for boiler itself )anyhow

Bruthal

DublinDilbert wrote: »

Oh did ya? very good.

PM me if you need any help or parts.

Sent you a PM about that.

MrThrifty

Just stumbled upon this thread. To the OP, maybe I'm crazy but I think what you're really looking for is simply a motorised valve with a built-in switch which closes when the valve is open. Often a boiler and pump is wired in series through this switch so as to ensure that they will never power up if the valve fails to open (and therefore the water cannot flow).

Bruthal

MrThrifty wrote: »

Just stumbled upon this thread. To the OP, maybe I'm crazy but I think what you're really looking for is simply a motorised valve with a built-in switch which closes when the valve is open. Often a boiler and pump is wired in series through this switch so as to ensure that they will never power up if the valve fails to open (and therefore the water cannot flow).

The OP knows all that i think, what he was after was for the motorised valve switch to close, and this switch closing operates a wireless transmitter to close a set of contacts on a receiver at the boiler to save himself the difficult task of wiring through an apartment.

nailer8

The system is up and running now. Just in time for the snow.
Works great, each zone is at the right temp when i need it.

I did cheat a bit though, i left out the third circuit for the hot tank.
Might do it some other time.
Basically i have
2 x TP7000Si-RF Wireless Programmable Room thermostats.
2 x RX3 3-Channel Receivers (one for the motorised valves and one for the boiler)

The RX3 receivers bring in the mv and the boiler at the same time.
Because the cylinder is always open there is no danger of the boiler running with nowhere for the water to go. The cylinder is really well insulated (stays hot for 24h) so i dont think there is much heat being wasted and even if it was it is in the middle of the apartment anyway where it is needed.

Bruthal

nailer8 wrote: »

The system is up and running now. Just in time for the snow.
Works great, each zone is at the right temp when i need it.

I did cheat a bit though, i left out the third circuit for the hot tank.
Might do it some other time.
Basically i have
2 x TP7000Si-RF Wireless Programmable Room thermostats.
2 x RX3 3-Channel Receivers (one for the motorised valves and one for the boiler)

The RX3 receivers bring in the mv and the boiler at the same time.
Because the cylinder is always open there is no danger of the boiler running with nowhere for the water to go. The cylinder is really well insulated (stays hot for 24h) so i dont think there is much heat being wasted and even if it was it is in the middle of the apartment anyway where it is needed.

Yes no reason it wont work that way. The main reason cylinder stats are used is because the hot water does not need to be heated as high a temp as the rads are usually set to, but its not a big problem really.

mazthespark

maybe a stupid idea... but could u not use another wireless thermostat kit?? put the thermostat in the hotpress and set it so that the contact will always be closed and put the reciever at the boiler (in essence giving you what you need) and feed the stat with the contacts from the motorised valves or whatever you want to use to switch on the boiler??

Bruthal

mazthespark wrote: »

maybe a stupid idea... but could u not use another wireless thermostat kit?? put the thermostat in the hotpress and set it so that the contact will always be closed and put the reciever at the boiler (in essence giving you what you need) and feed the stat with the contacts from the motorised valves or whatever you want to use to switch on the boiler??

The only thing is when you power on them stats i think you then have to set them to what ever setup mode you like. I dont thik they would just operate their contacts if you set the stat to 100c as example and then just power the stat on and off. But maybe it would and you could be right. I had thought of similar by using one of them remote wireless switches and connecting the motorised valve stats switch contacts to the remote button inside the hand controller, bit of messing though.

mazthespark

are some not powered from batteries? and just act as a switch?? meaning unless the batteries die they retain there state regardless whether there is voltage at the contacts or not?

Bruthal

Yes but how would you get the valve contacts to operate it. If you have a digital wireless stat set in the closed position, then remove the mains supply, im not sure when the mains supply is returned that it will just revert back to its closed contacts position again without intervention from the user. I could be wrong if course, just not sure about that. It will of course keep its time and date settings and temp setting etc.

It might work alright.

mazthespark

I see what your saying alright would depend on the stat you pick. if it kept its state before losing power it would be perfect and i know some do

strandsman

Hi guys, here's my situation, I have a solar panel heating my 300 litre tank for the hot press and hot water this is useful for the summer as the oil boiler heats the tank in the winter, I am thinking of a system where on a sunny day during winter when i've seen the roof panel temp rise to 80-90 degrees and it is topping up the heat in the tank from the boiler i'd like to take the heat out of the tank to heat the radiators during the day (when i am at work)and the boiler could take over during the nite.so I too am thinking fitting a transmitter between the tank and the boiler circulation pump so when the solar pump comes on a signal is sent to switch on the pump, it would be very difficult to run a wire, Am i right in thinking this could be done??