Numatic Henry HVR200A

[beko1987]

Ha I don't have a pHd in anything!

My stepdad poked it witha multimeter and confirmed it was dead. Sadly, and I've jsut realised he hasn't poked the new board...

However, he did recall a yarn to me. He works in electronics, has done since the 70's. Apparently, once, some US manufacturer made a power supply for a computer. Worked well abroad, they started selling them here. He had a broken one in for repair, and found that a certain component was only rated to X value. X value was fine in the US, but too low for the UK, which has Y value. 80% of the time, the product will work well, but if the load increases above X value, it breaks and kills the product. A change was made and it was all fixed etc.

Maybe, since these machines now go all over the world, something similar is happening here. Some component on that board cant take the heat/hi-lo switching cycles/constant high power. Of course one would need to browse foreign ebay to see what the failure rate is, but I bet alot of the abroad use is from companies who buy fleets of them.Enough of the fleet dies in a silly amount of time and bam - dropped from the books due to unreliability. So we may never know, as I doubt they go to ebay!

The switch is very simple, and mine was spotless inside. When the switch is flicked, it contacts thecontacts, which send the signal to change power to the pcb. (incase anyone thought it might be the switch)

Happy to post my dead board to someone more knowlegable if wanted! I'm getting quite interested in this!

 

[beko1987]

On that chip, the model id is only very different between the boards. Both made by the same company too.

That chip is my primary concern tbh. On my S5, the thermal fuse is very similar to that, just bigger. That had blown on the solder joints. But the whole module was replaceable (at eye watering cost from miele I assume!) as the chip was supposed to die first (after considerable red light of doom)

Same could be happening here either inadvertantly, or as a failsafe which is proving unreliable, hence the service item note on the new boards bag!

Manchestervacs, are you reading this? Any insight from a professional point of view? Know anyone who gets alot of henries in? Any trends?

 

[ultimatevacman]

I wouldn't worry about it, fitting a new PCB is cheap and easy.


 


I'm not too sure what that is, but whats funny is, in the Bertie, the PCB if facing away from the motor, but that piece seems to be on the other side facing the motor? I found it odd. I'll get some photos up tomorrow

 

[beko1987]

I agree, as a general issue for us especially, I'd rate it no more tricky than getting a motor out of a 1334! 'Service Item', get some in alongside your belts and bags for the rest of the fleet!

If you skipped the washing, drying, posing for photo's etc you'll be done in 15 minutes! All screws out, lift off the hat and take cord rewind out, lift the next bit up enough to slide the pcb out, swap the wires over and slide it back in. Re-assemble, job done.

 

[madabouthoovers]

That part is still on the side facing the motor as it needs to be in the path of the cooling air from the exhaust duct, which suggests it gets hot in use and even after the board was modified, it remains in the airflow.


It looks like a large transistor - a kind of switching relay.


 


If the henry has a thermal cutout, this is likely to be built onto or into the motor housing, which I haven't yet had a good gander at. I only opened up my Henry to see what type of board it had in it.

 

[ultimatevacman]

That would make sense.


 


Like I said, I'll have a proper look at it tomorrow and I'll take some pics.

 

[madabouthoovers]

Beko - with an electric screwdriver - turn the head over and remove all 7 screws, then lift up. The top comes off and reveals the board slotted in the ducting. I looked at it last night and its possible to change it in less than 2 minutes.


The big problem is that Joe Public wont know this and assume the motor has gone tits up when henry "just stops". Hence they will throw it out or sell it  on ebay without realising that they could get a "service item" for £20 or so to fix their Henry.

 

[ultimatevacman]

That's very true Steve. It's a shame people don't get things repaired anymore. *sigh*

 

[beko1987]

Very true! Y electric screwdriver was in the house, and I was in the garage... You see my dilemma

 

[ultimatevacman]

When I took my James and Bertie apart for the first time, the screws are very very stiff! An electric screwdriver would have been handy.

 

[ultimatevacman]

Sam, I get what you mean, I sometimes have situations like that, haha.

 

[madabouthoovers]

Looking up transistor on Wiki, it seems that the component marked with ?? is indeed a power switching transistor. It has three legs. when a small voltage is applied to the centre leg, it allows a certain current to flow through the other legs. So it effectively controls the resistance of the motor circuit between the Hi and Lo states. When in Lo, the input voltage to the centre leg changes the resistance of the circuit to increase it - and this lowers the current flow to the motor. The transistor then gets hot as its offering higher resistance to the current flow - hence the transistor is fixed to a heat sink, and this is in the airflow.

 

[moojuiceuk]

I wouldn't be surprised if that big black 3 legged component isn't actually a triac. The design may well be chopping the AC waveform to reduce power to the motor as a basic high/low speed controller. They're often used in dimmer light switches and for switching heating elements (I work for a heating company and see Triac's in more products these days).

I've got an older pre Autosave Henry here with the red footswitch and a green side hi-lo switch. If these also had a similar board inside I'd have a look to see if the AC supply is being chopped like I suspect.

 

[madabouthoovers]

Yours is the old type, 206606 -  2 terminal board, and will look like this:

 

[beko1987]

If it helps

 

[moojuiceuk]

Yep, just as I thought. It's a Triac, 12Amp rated.

http://www.st.com/web/en/resource/technical/document/datasheet/CD00161295.pdf

The circuit board is like a dimmer switch, fixed to a lower setting, chopping the AC waveform to reduce power to the motor. It's either getting too hot (no heatsinking, poor airflow) or like others have suggested, the carbon dust has snookered it.

If it's just that component that's failed and it hasn't killed anything else on the board, the Triac's are sold for about £1.29 + VAT from RS Components, part number 687-0947. If something else on the board has failed too, you might as well shell out the £15 on a re-designed PCB or just bypass the ruddy switch altogether

 

[parwaz786]

Well then if you want to keep your Eco Henry, I suggest buying a whole bunch of boards!


I was actually going to buy the exact Henry with the exact problem like Sam's one approx 2 months ago which went for £32 I think?

 

[madabouthoovers]

Thanks to MooJuice for his info - hopefully people will be able to find this thread in the future if their Henry suddenly "dies".


 


I think that with a heavy enough build up of carbon dust all over that circuit board, its bound to have caused a short somewhere, which was why Numatic had the majority of the circuitry turned round to the other side of the board, so that only the Triac faced the carbon dust flow.


Incidentally, there is a carbon filter wrapped round the motor, so maybe washing this out once a year might help reduce the instance of board failure?

 

[hi-loswitch98]

Steve are you on Facebook?

 

[madabouthoovers]

Hilo - no afraid not. Don't use facebook, nor Skype. I'm too old to understand all this new-fangled technology used by your age group lol.