Sealey trips out

[Cret]

Thanks for the suggestions.

Sorry if it's unclear - I realise I've written a lot.
To try and summarise though, consistently this is the deal:

1. 1st attempt to start compressor (hot or cold, full or empty) = house MCB trips for that circuit. Only seems to do this once each time, ie first try.
2. Empty tank starts are normally ok whether warm or cold.
3. Partially pressured starts tend to work when machine is warm but not cold.

Don't understand why the tank pressure matters when I've eliminated any valve issue fairly well I think from the investigation but who knows!


Will go and buy a C16 breaker tomorrow then if that's a good chance of being an influence here.
Are there various kinds or do I just go and ask for a C16 MCB breaker? And are they likely to sell them in B&Q in the electrical aisle?


Happy enough to try shorting the thermal trip thing on it as a temporary test. I'm pretty sure the fuse in that is a 16 amp rated one.

 

[brightspark]

Thanks for the suggestions.

Sorry if it's unclear - I realise I've written a lot.
To try and summarise though, consistently this is the deal:

1. 1st attempt to start compressor (hot or cold, full or empty) = house MCB trips for that circuit. Only seems to do this once each time, ie first try.
2. Empty tank starts are normally ok whether warm or cold.
3. Partially pressured starts tend to work when machine is warm but not cold.

Don't understand why the tank pressure matters when I've eliminated any valve issue fairly well I think from the investigation but who knows!


Will go and buy a C16 breaker tomorrow then if that's a good chance of being an influence here.
Are there various kinds or do I just go and ask for a C16 MCB breaker? And are they likely to sell them in B&Q in the electrical aisle?


Happy enough to try shorting the thermal trip thing on it as a temporary test. I'm pretty sure the fuse in that is a 16 amp rated one.

check what make the breaker is the conections to the busbar are all diffrent . take one out and match it up as some diffent makes will fit

 

[Cret]

Just been reading about various bus differences etc like you say.
This will sound a dumb question I'm sure, but whilst I've done bits of wiring around the house I've never had one of those MCBs out in the past as I haven't needed to.

Is it just a case of turn the overall house trip off then remove? Or is there more in depth procedure to them than that?

This is the Consumer Unit I have (fitted about 4-5 years ago). A Wylex I believe, so does that just mean I need a Wylex fitment MCB or do they vary as well?:

And this by the way is the inside of the capacitor/thermal trip housing on the compressor. The trip thing is labelled as 15A. Don't want to even think about touching it unless I know the capacitors aren't going to have juice in them and make me jump across the garage with a blast!!

 

[brightspark]

Just been reading about various bus differences etc like you say.
This will sound a dumb question I'm sure, but whilst I've done bits of wiring around the house I've never had one of those MCBs out in the past as I haven't needed to.

Is it just a case of turn the overall house trip off then remove? Or is there more in depth procedure to them than that?

This is the Consumer Unit I have (fitted about 4-5 years ago):

And this by the way is the inside of the capacitor/thermal trip housing on the compressor. The trip thing is labelled as 15A. Don't want to even think about touching it unless I know the capacitors aren't going to have juice in them and make me jump across the garage with a blast!!

if u change the breaker in the consumer unit u will have to loosen all the bottom busbar rail off. drop it down take out breaker then replace new one . making sure the clamps are pushed back in each breaker before re fitting the capacitors can hold the charge for a few minutes after use , just short them out with a screwdriver across the conections. if charged they will just spark and discharge

 

[eil]

Did your sparky check the current draw of the motor at start up and when running.

 

[tigler]

The cause of the house MCB tripping initially then being ok may be the surge of the caps charging after being completely discharged. Caps normally have bleed off resistors connected across them to discharge them for safety. If they don't and to satisfy your concern for safety, leave them for about 20 minutes after turning the compressor off and unplugging, then stick a screwdriver or insulated pliers across the terminals for about 10 seconds, they will be discharged after that.
To fit the MCB you will need to remove the cover from the consumer unit, after turning off. Then the MCB can be pulled or prised out of the bus rails and the new one clipped in.

 

[Cret]

Did your sparky check the current draw of the motor at start up and when running.

Not that I know of no. I hadn't called him out as it happened, he'd just turned up at my house for a natter and a brew by chance as I was about to text him to ask about the compressor, so he didn't have all his gear with him as he wasn't in his van.

Like I say though he did suggest changing the fuse to a C type one but then I think perhaps subsequently was under the impression the problem had gone away (or something - I forget the details as it was a while ago).

Re' removing/replacing the MCB - is it the case then that with the main trip off (ie the overall switch on the right of the unit) that there will still be exposed live stuff in the consumer unit when I remove that front cover to loosen the bus? And will the bus bar itself be live? Fine if it is, but I just want to be sure I have no surprises.

I've had my fair share of mains jolts in the past but they're not really pleasant so I really would rather be as safe and sensible as possible!

Appreciate all these speedy replies by the way - it's very helpful indeed, thanks.

 

[brightspark]

Not that I know of no. I hadn't called him out as it happened, he'd just turned up at my house for a natter and a brew by chance as I was about to text him to ask about the compressor, so he didn't have all his gear with him as he wasn't in his van.

Like I say though he did suggest changing the fuse to a C type one but then I think perhaps subsequently was under the impression the problem had gone away (or something - I forget the details as it was a while ago).

Re' removing/replacing the MCB - is it the case then that with the main trip off (ie the overall switch on the right of the unit) that there will still be exposed live stuff in the consumer unit when I remove that front cover to loosen the bus? And will the bus bar itself be live? Fine if it is, but I just want to be sure I have no surprises.

I've had my fair share of mains jolts in the past but they're not really pleasant so I really would rather be as safe and sensible as possible!

Appreciate all these speedy replies by the way - it's very helpful indeed, thanks.

if the main switch is turned off the only live part is at the incomer part of the main switch where the mains tails are on the top not the outgoing busbar

 

[Cret]

Great - that suits me fine thanks.

Cheers Tigler for the caps info too.

 

[Cret]

Just to clarify - is this the correct MCB I'll need for this task then?
http://www.ebay.co.uk/itm/WYLEX-PSB...ittings_MJ&hash=item4160a87385#ht_1569wt_1396

 

[brightspark]

Just to clarify - is this the correct MCB I'll need for this task then?
http://www.ebay.co.uk/itm/WYLEX-PSB...ittings_MJ&hash=item4160a87385#ht_1569wt_1396

yup thats dear though im tight supose its ok for del to the isle

 

[Cret]

Great - cheers

 

[eil]

With your multimeter I would check the voltage on the motor terminals when you switch it on to make sure its getting its rated voltage, then with a clamp meter check the amp draw at start up and check that its not exceeding the LRA stated on the motors rating plate, then note the running amp draw which in turn should not exceed whats on the rating plate. It wont hurt to give it a bit of running in time with the discharge pipe taken off either just in case.

 

[rtbcomp]

Also check the belt tension. On mine (Clarke) a slack belt slipped at full compression, then the motor stalled.

 

[Cret]

Hmmm, don't have a clamp meter but I can buy one somewhere I suppose.

Belt tension seems ok from what I can tell. Might be worth a closer look or mess with though from what you've said rtbcomp. Can't hurt, specially since Clarke and Sealey products usually strike me as being one & the same thing (I may be wrong).

Well, I went and got a B20 MCB today just to temporarily try in place of the B16 MCB currently connected to.
The behaviour is exactly the same except that the very first startup attempt does not make the MCB trip. They didn't have any C type motor ones at the shop so this was the next best thing. It hasn't tripped out yet, but the thermal trip on the compressor is still doing just as before.

So tonight it went as follows:
1st start try - (empty tank) compressor started and ran. I let it go to about 70psi then turned it off.
2nd start try - turned it back on again a few seconds later. It started ok and ran, then I turned it back off after a few more seconds.
3rd/4th/5th/6th start try - tripped the thermal breaker.

So what to try next?

I did notice that when it was trying to start and was failing it seemed to be turning over slowly (ie the several revolutions before the trip goes).
I think I have fairly well ruled out pressure problems as I just can't see how that could be possible given all the stuff tested so far.

Could this symptom point further to unhealthy capacitors???? I don't know enough about capacitors to know if they're capable of causing an intermittent problem like this?

Here are pictures of them anyway in case there's anything conspicuous (can't see why there would be but still.....):

Then the other one (4 terminals instead of 2, albeit 3 in use):

And the thermal breaker unit:

Do any of these look like awful quality items that may well have failed on the principle that they're just plain sh1t, and likely to cause problems?
Is there any point say in replacing the 150mf start one with a more powerful one to give a starting boost above what it already has?

The blue one states on it that it's a motor starting capacitor - the other is a run capacitor I believe, but I'm not sure I understand why that is required once the motor is running?

And is that likely to be a resistor beneath the heatshrink on the start one, ie as people have described for draining the stored juice after power is turned off?

 

[Cret]

Just ordered a clamp meter anyway. Will come in handy as a spare multimeter if nothing else for when I've left mine in a stupid place...

 

[brightspark]

Just ordered a clamp meter anyway. Will come in handy as a spare multimeter if nothing else for when I've left mine in a stupid place...

i hope u have bought one with inrush current otherwise it wont be much use

 

[Cret]

Errrr, one of these. It's cheap so if that's a non default feature I'd guess not.
http://cgi.ebay.co.uk/ws/eBayISAPI....78&ssPageName=ADME:L:OC:GB:1123#ht_778wt_1163
Doh!

On the plus side I note it has an audible tone for continuity which my current meter doesn't have and I miss from my previous one, so if nothing else it'll make me happier when I have to test continuity that I don't have to have the display in view (sure we all know how fiddly that can be when balancing the meter on something and holding both probes at funny angles etc!!!)

 

[brightspark]

Errrr, one of these. It's cheap so if that's a non default feature I'd guess not.
http://cgi.ebay.co.uk/ws/eBayISAPI....78&ssPageName=ADME:L:OC:GB:1123#ht_778wt_1163
Doh!

fraid not there about £110 quid the cheapest

 

[Cret]

Ahhh. See that's useful as I've learned something today now.

Ah well. My sparky is pretty tame so I can probably bribe him with a cuppa to test this aspect for me. I can go off and google/learn myself about inrush current.
*Edit* looking quickly it doesn't look like a difficult concept!

What is the point of the clamp meters claiming to handle 1000amps if they can't deal with an initial spike? Surely it'd be way less than the claimed rating for the meter?