Cooker hood schematic, can anyone help?

[phatboy]

The point of this operation, is that I want to activate the boost function of my MHRV system when the cooker hood is turned on, regardless of its speed setting.

The hood is a Caple CGC610

I've opened it up, and found that there are 6 wires going to the motor, however 2 of them connect to this capacitor (?). Sadly my photo of the wiring connector didn't work and I've closed the thing up again now. It did however have 4 connections, labelled on the PCB according to the colour of the cable and nothing else.

There is also a nice wiring schematic I found, but I cannot tally it with what I'm seeing.

Hopefully someone with more electronics knowledge can help me understand how it works, and if indeed there will be a constant 'live' wire when it is in operation.

Many thanks for any help!
Tim

 

[JohnD]

presumably you have an isolating switch or FCU on the wall to turn power to the hood on and off?

It might be easier to use the on/off switch on the wall to control your ventilation system. Turn the wall switch off when you don't need the hood running.

 

[jj4091]

Or use this in conjunction with the light rather than the fan https://www.ebay.co.uk/itm/12v-ac-d...375343?hash=item1ccec92e2f:g:-vUAAOSwDV1XRFr0

 

[mattylad]

How do you want this to be able to work?
i.e. What do you want to have to do and then what do you want to happen and for how long?
(Please do not use the word "boost" as that suggests you want it to go faster than the high setting.)

From that schematic the 240vAC motor has a permanent Neutral connection and the live is switched to different windings by the "control switch" (it would be better to be able to see all this too?).
If the "control switch" is in fact just a switch then tapping into the "high" winding connection with a switched live would do it if done correctly.

 

[bernardgreen]

there are 6 wires going to the motor, however 2 of them connect to this capacitor (?).

Hence the 6 leads from the motor.

the boost function of my MHRV

How is this controlled ? . Is the control input a switch that is connected to the MHRV control unit or does the MHRV require a Switched Live connected to the control unit ?

 

[oldbutnotdead]

First one- how is the boost function on your MHRV setup triggered? Is it part of the system control box or is it an external switch?

Second one- no there's not a convenient single 240v live that goes high when your cooker hood is on.

But (if you have a multimeter and can safely access those 4 wires while the hood is live) you should find that all 3 of the wires (marked LOW, MIDDLE and HIGH) go high when the fan control switch is in any position other than OFF (meter set to read 250v AC).
If that is the case then a 240v relay across LOW and N should give you your switch function (as a volt free switch)- once you unveil the MHRV wiring then an interface should be possible.

 

[phatboy]

Wow thanks for all the replies!

presumably you have an isolating switch or FCU on the wall to turn power to the hood on and off?

It might be easier to use the on/off switch on the wall to control your ventilation system. Turn the wall switch off when you don't need the hood running.

That switch is too high for general day-to-day operation.

Or use this in conjunction with the light rather than the fan https://www.ebay.co.uk/itm/12v-ac-d...375343?hash=item1ccec92e2f:g:-vUAAOSwDV1XRFr0

If I cannot get a supply from the fan itself, I will have to go down this route.

How do you want this to be able to work?
i.e. What do you want to have to do and then what do you want to happen and for how long?
(Please do not use the word "boost" as that suggests you want it to go faster than the high setting.)

From that schematic the 240vAC motor has a permanent Neutral connection and the live is switched to different windings by the "control switch" (it would be better to be able to see all this too?).
If the "control switch" is in fact just a switch then tapping into the "high" winding connection with a switched live would do it if done correctly.

I just quoted the manufacturer of the system, who say it runs in background mode, boost, or purge!

I want to select any of the 3 speeds on the extractor, and have that trigger the 'boost' function of the MHRV unit. It has a number of volt-free terminals available, and I've found a timer relay that accepts a wide input voltage, so would work for this I think

View attachment 162420
Hence the 6 leads from the motor.

How is this controlled ? . Is the control input a switch that is connected to the MHRV control unit or does the MHRV require a Switched Live connected to the control unit ?

Thanks, my electronic knowledge is clearly lacking! I'm unsure exactly what you are asking, but the unit has volt-free (0-10v) terminals with in and out, which I want to use.

First one- how is the boost function on your MHRV setup triggered? Is it part of the system control box or is it an external switch?

Second one- no there's not a convenient single 240v live that goes high when your cooker hood is on.

But (if you have a multimeter and can safely access those 4 wires while the hood is live) you should find that all 3 of the wires (marked LOW, MIDDLE and HIGH) go high when the fan control switch is in any position other than OFF (meter set to read 250v AC).
If that is the case then a 240v relay across LOW and N should give you your switch function (as a volt free switch)- once you unveil the MHRV wiring then an interface should be possible.

The boost is triggered by any of the 4 available volt-free pairs of terminals, so its integral to the unit (Expensive external options are available)

I thought maybe low would always be powered if the fan was running, as it may be cumulative through speed settings 1 - 3. I haven't put the meter on the terminals yet, as I wanted a little guidance before I started 'having a go'.

I'll give that a shot tomorrow evening.

Many thanks everyone again, I'm overwhelmed with the useful replies!

Tim

 

[phatboy]

This is the unit I have been looking at the take the variable input voltage from the extractor, and it also has convenient options for setting up an over-run

https://www.rapidonline.com/GIC-1CM...MI5Myc_In84AIVhrHtCh29KQSZEAQYAyABEgI0jvD_BwE

 

[SUNRAY]

First one- how is the boost function on your MHRV setup triggered? Is it part of the system control box or is it an external switch?

Second one- no there's not a convenient single 240v live that goes high when your cooker hood is on.

But (if you have a multimeter and can safely access those 4 wires while the hood is live) you should find that all 3 of the wires (marked LOW, MIDDLE and HIGH) go high when the fan control switch is in any position other than OFF (meter set to read 250v AC).
If that is the case then a 240v relay across LOW and N should give you your switch function (as a volt free switch)- once you unveil the MHRV wiring then an interface should be possible.

Make sure you connect the relay across the HIGH wire and use a relay which will switch at a much lower voltage.
When the fan is running at high speed, the low wire is likely to be at vastly higher voltage.

 

[phatboy]

So I have now tested, and got the following results:

High
246v
206v
163v

Medium
274v
246v
193v

Low
311v
279v
246v

At least I think thats the right order, I couldn't completely determine which speed was on which pin from what I saw.

So as @SUNRAY has suggested, I should connect across the HIGH setting.

Any thoughts on the suitability of the overrun relay I have found, or any alternatives? This is all going to work out quite nicely

Thanks
Tim

 

[SimonH2]

Those numbers look reasonable, and yes I think that relay should do it.
As Sunray says, the low and medium speed connections on these multi-speed motors can be significantly higher in voltage than the supply - the motor acts as an auto-transformer stepping up the voltage.

 

[SUNRAY]

Those numbers look reasonable, and yes I think that relay should do it.
As Sunray says, the low and medium speed connections on these multi-speed motors can be significantly higher in voltage than the supply - the motor acts as an auto-transformer stepping up the voltage.

Yes that timer relay looks to be suitable make sure you order the 1Cxxxxx version as others in the range a dual voltage rather than variable. I default to Edwardes Brothers wholesalers for much of my supplies and queeries and have always found them to be very helpful.

Does your MHRV have a built in timer facility avaiable? You may not only need a simple relay and not the expense of this additional timer.

 

[phatboy]

Yes that timer relay looks to be suitable make sure you order the 1Cxxxxx version as others in the range a dual voltage rather than variable. I default to Edwardes Brothers wholesalers for much of my supplies and queeries and have always found them to be very helpful.

Does your MHRV have a built in timer facility avaiable? You may not only need a simple relay and not the expense of this additional timer.

Cool thanks,

Any suggestions for a suitable enclosure for it? It is the only DIN type device I will have so I am not sure it justifies a case (Unless very cheap!), or whether I can just put it inside a plastic box with a screw-closed front.

MHRV timer - well, I don't think so but I called Vent Axia who said it does, but the advice they gave contradicts the manual!

If I was able to do it that way, can you suggest a suitable device? If it's only a few £ I could try that option first I suppose....

Thanks
Tim

 

[phatboy]

Any suggestions for a suitable enclosure for it? It is the only DIN type device I will have so I am not sure it justifies a case (Unless very cheap!), or whether I can just put it inside a plastic box with a screw-closed front.

Found a cheap one! Was searching badly.

 

[SimonH2]

This is a handy and cheap 2 module enclosure - you'll need a blank if you only have the one module used.