CH decided to fail today - chose a nice Spring day, so I can't complain too
much.

Pump body is hot, far hotter than it should be with no gas burning
(integrated combi Vokera)

There's a great big capacitor in the connection box, scorched and split
open.

If I cut it out of the circuit, will the pump run until I can replace it?

Do the connections need to be joined for that?

(Bizarrely, the fault code is d1, condensate trap blocked. But I've
dismantled and checked that)

Thanks if any can advise?


---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On 08/04/2014 21:40, Steve Walker wrote:
CH decided to fail today - chose a nice Spring day, so I can't complain too
much.

Pump body is hot, far hotter than it should be with no gas burning
(integrated combi Vokera)

There's a great big capacitor in the connection box, scorched and split
open.

If I cut it out of the circuit, will the pump run until I can replace it?

No. It's a motor start or run capacitor. The motor needs it to start
turning. The motor will be hot because it is not turning and is hence
drawing a higher current than normal.

http://en.wikipedia.org/wiki/Motor_capacitor

Hopefully the body isn't too scorched to read the specification as you
need to replace it with a capacitor intended for motor start or run use
(as appropriate) with the same capacitance and voltage rating.

It is important not to use a polarised capacitor intended for DC use
(will have + and - marking on terminals) in an AC motor application.


--
Graham Nye
news(a)thenyes.org.uk

Yes it is used to phase shift the supply to start it running in the right
direction as far as I can recall. It might of course itself, ie the motor
that caused a problem so it might be best to replace the module rather than
faff about just replacing the capacitor.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Graham Nye" wrote in message
...
On 08/04/2014 21:40, Steve Walker wrote:
CH decided to fail today - chose a nice Spring day, so I can't complain
too
much.

Pump body is hot, far hotter than it should be with no gas burning
(integrated combi Vokera)

There's a great big capacitor in the connection box, scorched and split
open.

If I cut it out of the circuit, will the pump run until I can replace
it?

No. It's a motor start or run capacitor. The motor needs it to start
turning. The motor will be hot because it is not turning and is hence
drawing a higher current than normal.

http://en.wikipedia.org/wiki/Motor_capacitor

Hopefully the body isn't too scorched to read the specification as you
need to replace it with a capacitor intended for motor start or run use
(as appropriate) with the same capacitance and voltage rating.

It is important not to use a polarised capacitor intended for DC use
(will have + and - marking on terminals) in an AC motor application.


--
Graham Nye
news(a)thenyes.org.uk

"Graham Nye" wrote in message
...
On 08/04/2014 21:40, Steve Walker wrote:
CH decided to fail today - chose a nice Spring day, so I can't complain
too
much.

Pump body is hot, far hotter than it should be with no gas burning
(integrated combi Vokera)

There's a great big capacitor in the connection box, scorched and split
open.

If I cut it out of the circuit, will the pump run until I can replace
it?

No. It's a motor start or run capacitor. The motor needs it to start
turning. The motor will be hot because it is not turning and is hence
drawing a higher current than normal.

http://en.wikipedia.org/wiki/Motor_capacitor

Hopefully the body isn't too scorched to read the specification as you
need to replace it with a capacitor intended for motor start or run use
(as appropriate) with the same capacitance and voltage rating.

It is important not to use a polarised capacitor intended for DC use
(will have + and - marking on terminals) in an AC motor application.

Thanks Graham - so the winding acts as a heater element instead of turning?

I've located what seems to be a suitable match (ebay 251275119724)
2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.

Much appreciated.

"Brian Gaff" wrote in message
...
Yes it is used to phase shift the supply to start it running in the right
direction as far as I can recall. It might of course itself, ie the motor
that caused a problem so it might be best to replace the module rather
than faff about just replacing the capacitor.

Thanks Brian - I tested the resistance of the motor as suggested here -
http://www.pumptool.co.uk/Combi%20Boilers.html#windings

My £5 multimeter read a steady 180 Ohms, and the impeller shaft spins
smoothly, so I have my fingers crossed.

If I have to change whole pump it's not so bad, but obviously hoping not to.

On Tuesday, April 8, 2014 11:31:01 PM UTC+1, Steve Walker wrote:

Thanks Graham - so the winding acts as a heater element instead of turning?
I've located what seems to be a suitable match (ebay 251275119724)
2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.
Much appreciated.

£7.29 for a 2.5uF cap, ye gods. At that price I'd raid the junkboxes to assemble 2x 5uF 400v caps in series.


NT

On 09/04/2014 09:30, wrote:
On Tuesday, April 8, 2014 11:31:01 PM UTC+1, Steve Walker wrote:

Thanks Graham - so the winding acts as a heater element instead of turning?
I've located what seems to be a suitable match (ebay 251275119724)
2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.
Much appreciated.

£7.29 for a 2.5uF cap, ye gods. At that price I'd raid the junkboxes to assemble 2x 5uF 400v caps in series.

Does seem a bit overpriced. Rapids are about £2.50 + postage.

Rapid don't have a cheap 2.5uF but I expect 2 or 3uF would do almost as
well - provided that it isn't that the motor has completely seized up.

http://www.rapidonline.com/Electroni...Run-Capacitors

--
Regards,
Martin Brown

On 09/04/2014 09:30, wrote:
On Tuesday, April 8, 2014 11:31:01 PM UTC+1, Steve Walker wrote:

Thanks Graham - so the winding acts as a heater element instead of turning?

Yes.

I've located what seems to be a suitable match (ebay 251275119724)
2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.
Much appreciated.

£7.29 for a 2.5uF cap, ye gods. At that price I'd raid the junkboxes
to assemble 2x 5uF 400v caps in series.

You could, if you don't mind the risk of a couple of aging electrolytics
with insufficient ripple current rating exploding. Most people would prefer
to fit the proper part for the job and think that £7-odd was a well-spent
alternative to a boiler call-out fee.




--
Graham Nye
news(a)thenyes.org.uk

On Wednesday, April 9, 2014 5:15:55 PM UTC+1, Graham Nye wrote:
On 09/04/2014 09:30, wrote:
On Tuesday, April 8, 2014 11:31:01 PM UTC+1, Steve Walker wrote:

Thanks Graham - so the winding acts as a heater element instead of turning?

Yes.

I've located what seems to be a suitable match (ebay 251275119724)
2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.
Much appreciated.

£7.29 for a 2.5uF cap, ye gods. At that price I'd raid the junkboxes
to assemble 2x 5uF 400v caps in series.

You could, if you don't mind the risk of a couple of aging electrolytics
with insufficient ripple current rating exploding. Most people would prefer
to fit the proper part for the job and think that £7-odd was a well-spent
alternative to a boiler call-out fee.

Why would you use lytics? Why would you fit an underspecced part? Honestly.


NT

"Martin Brown" wrote in message
...
On 09/04/2014 09:30, wrote:
On Tuesday, April 8, 2014 11:31:01 PM UTC+1, Steve Walker wrote:

Thanks Graham - so the winding acts as a heater element instead of
turning?
I've located what seems to be a suitable match (ebay 251275119724)
2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.
Much appreciated.

£7.29 for a 2.5uF cap, ye gods. At that price I'd raid the junkboxes to
assemble 2x 5uF 400v caps in series.

Does seem a bit overpriced. Rapids are about £2.50 + postage.

Rapid don't have a cheap 2.5uF but I expect 2 or 3uF would do almost as
well - provided that it isn't that the motor has completely seized up.

http://www.rapidonline.com/Electroni...Run-Capacitors

Thanks, I'll save that link - but to be honest, I'm not unhappy with £7
through the letterbox tomorrow. We have no heating, I'm tied up working
long hours and can't easily get to a parts supplier, so it works out OK.

Fingers crossed!

On 09/04/2014 19:47, wrote:
On Wednesday, April 9, 2014 5:15:55 PM UTC+1, Graham Nye wrote:
On 09/04/2014 09:30, wrote:
On Tuesday, April 8, 2014 11:31:01 PM UTC+1, Steve Walker wrote:

2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.

£7.29 for a 2.5uF cap, ye gods. At that price I'd raid the junkboxes
to assemble 2x 5uF 400v caps in series.

You could, if you don't mind the risk of a couple of aging electrolytics
with insufficient ripple current rating exploding. Most people would prefer
to fit the proper part for the job and think that £7-odd was a well-spent
alternative to a boiler call-out fee.

Why would you use lytics? Why would you fit an underspecced part? Honestly.

If you've got a junkbox with spare motor-rated capacitors, fine. Use them.

If your junkbox has an electronics focus then keep your 400 V electrolytics
for valve use, not motors.



--
Graham Nye
news(a)thenyes.org.uk

On Wednesday, April 9, 2014 10:53:05 PM UTC+1, Graham Nye wrote:
On 09/04/2014 19:47, wrote:
On Wednesday, April 9, 2014 5:15:55 PM UTC+1, Graham Nye wrote:
On 09/04/2014 09:30, wrote:
On Tuesday, April 8, 2014 11:31:01 PM UTC+1, Steve Walker wrote:

2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.
£7.29 for a 2.5uF cap, ye gods. At that price I'd raid the junkboxes
to assemble 2x 5uF 400v caps in series.
You could, if you don't mind the risk of a couple of aging electrolytics
with insufficient ripple current rating exploding. Most people would prefer
to fit the proper part for the job and think that £7-odd was a well-spent
alternative to a boiler call-out fee.

Why would you use lytics? Why would you fit an underspecced part? Honestly.

If you've got a junkbox with spare motor-rated capacitors, fine. Use them..

I dont

If your junkbox has an electronics focus then keep your 400 V electrolytics
for valve use, not motors.

800v non-self healing is fine for motors, unless you can come up with a sensible reason why not.


NT

On 10/04/2014 01:23, wrote:
On Wednesday, April 9, 2014 10:53:05 PM UTC+1, Graham Nye wrote:
On 09/04/2014 19:47, wrote:
On Wednesday, April 9, 2014 5:15:55 PM UTC+1, Graham Nye wrote:
On 09/04/2014 09:30, wrote:
On Tuesday, April 8, 2014 11:31:01 PM UTC+1, Steve Walker wrote:

2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.
£7.29 for a 2.5uF cap, ye gods. At that price I'd raid the junkboxes
to assemble 2x 5uF 400v caps in series.
You could, if you don't mind the risk of a couple of aging electrolytics
with insufficient ripple current rating exploding. Most people would prefer
to fit the proper part for the job and think that £7-odd was a well-spent
alternative to a boiler call-out fee.

Why would you use lytics? Why would you fit an underspecced part? Honestly.

If you've got a junkbox with spare motor-rated capacitors, fine. Use them.

I dont

So you don't have correctly specced parts.

If your junkbox has an electronics focus then keep your 400 V electrolytics
for valve use, not motors.

800v non-self healing is fine for motors, unless you can come up with a
sensible reason why not.

If you want to use a component for an application it is not rated
for, or sold as suitable for, it is up to you, not me, to decide
if it is suitable for that application.




--
Graham Nye
news(a)thenyes.org.uk

"Steve Walker" wrote in message
...

Thanks, I'll save that link - but to be honest, I'm not unhappy with £7
through the letterbox tomorrow. We have no heating, I'm tied up working
long hours and can't easily get to a parts supplier, so it works out OK.

Back of the net!

Hooked the new capacitor up temporarily with Wago lever connectors, waited a
minute for it to absorb some charge and everything started up lovely.

One last (self-inflicted) question. How long for the cap to discharge
before I can permanently join it up with solder and heatshrink sleeving?
If I take it out of the circuit and leave it for an hour, or more? Is
there a safe way to discharge the stored energy?

Thanks to Graham & Brian for the brilliant help!

On 10/04/2014 20:30, Steve Walker wrote:

"Steve Walker" wrote in message
...

Thanks, I'll save that link - but to be honest, I'm not unhappy with
£7 through the letterbox tomorrow. We have no heating, I'm tied up
working long hours and can't easily get to a parts supplier, so it
works out OK.

Back of the net!

Hooked the new capacitor up temporarily with Wago lever connectors,
waited a minute for it to absorb some charge and everything started up
lovely.

One last (self-inflicted) question. How long for the cap to discharge
before I can permanently join it up with solder and heatshrink sleeving?
If I take it out of the circuit and leave it for an hour, or more? Is
there a safe way to discharge the stored energy?


As` it's connected to AC, not long, as the charge reverses 100 times a
second in service. Just leave it connected to the circuit for a few
moments after you try to start it with the power off.

--
Tciao for Now!

John.

On 10/04/2014 20:30, Steve Walker wrote:

Hooked the new capacitor up temporarily with Wago lever connectors, waited a
minute for it to absorb some charge and everything started up lovely.

Good.

One last (self-inflicted) question. How long for the cap to discharge
before I can permanently join it up with solder and heatshrink sleeving?
If I take it out of the circuit and leave it for an hour, or more? Is
there a safe way to discharge the stored energy?

It should discharge immediately on power-off through the motor windings.
You can check that has happened with your £5 multimeter. Set it on a
300 - 1000 Volt DC range and put the probes across the capacitor. If there
is an appreciable reading it should discharge over a couple of minutes
if you have a digital meter, or much faster if it is an analogue model.

You don't need to wait for the capacitor to absorb charge. This is a
mains AC application so the capacitor is charging and discharging twice
per cycle, hence 100 times per second.

Thanks to Graham [& Brian] for the brilliant help!

You're welcome. Thanks for the feedback.


--
Graham Nye
news(a)thenyes.org.uk

Steve Walker formulated the question :
"Steve Walker" wrote in message
...

Thanks, I'll save that link - but to be honest, I'm not unhappy with £7
through the letterbox tomorrow. We have no heating, I'm tied up working
long hours and can't easily get to a parts supplier, so it works out OK.

Back of the net!

Hooked the new capacitor up temporarily with Wago lever connectors, waited a
minute for it to absorb some charge and everything started up lovely.

One last (self-inflicted) question. How long for the cap to discharge
before I can permanently join it up with solder and heatshrink sleeving? If I
take it out of the circuit and leave it for an hour, or more? Is there a
safe way to discharge the stored energy?

Thanks to Graham & Brian for the brilliant help!

I don't quite understand the 'leave a minute to charge up'.

These things normally discharge very quickly, if you doubt it, just
short the terminals with a screwdriver etc. to discharge it.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Fri, 11 Apr 2014 15:35:53 +0100, Harry Bloomfield
wrote:

Steve Walker formulated the question :
"Steve Walker" wrote in message
...

Thanks, I'll save that link - but to be honest, I'm not unhappy with £7
through the letterbox tomorrow. We have no heating, I'm tied up working
long hours and can't easily get to a parts supplier, so it works out OK.

Back of the net!

Hooked the new capacitor up temporarily with Wago lever connectors, waited a
minute for it to absorb some charge and everything started up lovely.

One last (self-inflicted) question. How long for the cap to discharge
before I can permanently join it up with solder and heatshrink sleeving? If I
take it out of the circuit and leave it for an hour, or more? Is there a
safe way to discharge the stored energy?

Thanks to Graham & Brian for the brilliant help!

I don't quite understand the 'leave a minute to charge up'.

These things normally discharge very quickly, if you doubt it, just
short the terminals with a screwdriver etc. to discharge it.

The normal wiring of the run capacitor prevents it storing a charge
when the motor supply is turned off/disconnected. About the only way
of realising this risk (up to a max of 350ish volts) is to disconnect
the cap whilst the motor is live and running, not something anyone is
likely to do unless they're 'experimenting' (in which case, they aught
to be well aware of this risk).
--
Regards, J B Good

On Thursday, April 10, 2014 7:34:38 PM UTC+1, Graham Nye wrote:
On 10/04/2014 01:23, wrote:
On Wednesday, April 9, 2014 10:53:05 PM UTC+1, Graham Nye wrote:
On 09/04/2014 19:47, wrote:
On Wednesday, April 9, 2014 5:15:55 PM UTC+1, Graham Nye wrote:
On 09/04/2014 09:30, wrote:
On Tuesday, April 8, 2014 11:31:01 PM UTC+1, Steve Walker wrote:

2.5uf, 2.5mfd, Motor Run Capacitor, Bipolar 400v, 450v, 50/60 Hz,
- a cheap fix at £7.29, if it works out.
£7.29 for a 2.5uF cap, ye gods. At that price I'd raid the junkboxes
to assemble 2x 5uF 400v caps in series.
You could, if you don't mind the risk of a couple of aging electrolytics
with insufficient ripple current rating exploding. Most people would prefer
to fit the proper part for the job and think that £7-odd was a well-spent
alternative to a boiler call-out fee.
Why would you use lytics? Why would you fit an underspecced part? Honestly.
If you've got a junkbox with spare motor-rated capacitors, fine. Use them.
I dont

So you don't have correctly specced parts.

wrong

If your junkbox has an electronics focus then keep your 400 V electrolytics
for valve use, not motors.

800v non-self healing is fine for motors, unless you can come up with a
sensible reason why not.

If you want to use a component for an application it is not rated
for, or sold as suitable for, it is up to you, not me, to decide
if it is suitable for that application.

I did. Then you decided standard 800v plastic film wasnt suitable, so you tell us why. Its that or hot air.


NT