H & M Clipper help required

[DCB]

RCD   "Arsie Dee" is a generic term,   It is in the 17th and 18th editions of the UK wiring regulations which state which (and its almost all,) circuits now need RCD protection.  This can be an RCD, RCCB, RCBO or several other devices, the key thing is that they detect residual currents of 30ma or more.   If an electrician speaks of a  "Thirteen Amp Arsie Dee" it is an  RCBO which includes the overload trip  Junctionmad refers to.  The "Thirteen Amp," means the overload, the 30ma residual trip current doesn't need to be mentioned as it is pretty much industry standard but the overload varies, 5, 15. 30 amp etc  depending on the wiring in the circuit it is installed to protect.  An "Arsie Dee" can be a RCD  (no overload protection, that is in the fused plug) if its a stand alone RCD as used on your heritage Black and Decker hedge trimmer or an RCBO  (with its own overload protection) if its under your stairs in the fuse box.  We still call RCBOs  MCBs at our Village as they look like Miniature Circuit breakers and in fact replace miniature circuit breakers in the distribution boxes.  With a stand alone  RCD on each box  deals with 30ma blow the RCBOs only trip with an overload as the RCD always trips first for a residual current.  It really achieved sod all fitting RCBOs to boxes with RCDs

We still have the old Earth Leakage trip in our house so again everything shuts down if we have a fault..  

Edited September 21, 2019 by DavidCBroad
Crossland

[WIMorrison]

I have always gone by the mantra of stopping digging the hole before the ladder get too short for me to escape - works well.

[RLWP]

4 hours ago, WIMorrison said:

I have always gone by the mantra of stopping digging the hole before the ladder get too short for me to escape - works well.

 

Could you throw me down a rope?

[Crosland]

10 hours ago, AndyID said:

 

RCD - Residual Current Device is pretty obscure terminology.

 

It's common terminology for any recent installation on the UK. Whole house RCDs are fitted in new builds and rewires. Sometimes a non-RCD circuit will be installed for freezers to prevent food wastage if the RCD trips and isn't discovered for some time. I understand that US homes often only have GFI for the bathrooms.

 

6 hours ago, RLWP said:

Isn't is because they sort of subtract current from one wire from current in another. The difference should be zero, if it isn't the residual from the sum triggers the switch

 

That's right. Anything flowing through the live must be balanced by the return through the neutral.

[Crosland]

5 hours ago, DavidCBroad said:

RCD   "Arsie Dee" is a generic term,    "Thirteen Amp Arsie Dee" is one of those RCBOs which include an overload trip which Junctionmad refers to and an "Arsie Dee" can be a RCD if its a stand alone as used on your heritage Black and Decker hedge trimmer or an RCBO if its under your stairs in the fuse box.    We still have the old Earth Leakage trip in our house.  

 

Sigh.

 

RCD is a very specific term. An RCD is always an RCD.

 

An RCBO is more than just an RCD. An RCBO is generally found in the consumer unit and include the breaker (i.e. cuts the power on an overload) as well as RCD function.

 

A thirteen Amp RCD would be very, very dangerous. I will leave you to do the research to understand why RCDs are rated in milliAmps. Do let us know what you find out.

[Junctionmad]

18 hours ago, Porkscratching said:

I've 'done' fuses with a bit off a nail too..

Needless to say I also won't be taking the advice of the bloke earlier to not use my old H&M transformers, they work for my purposes ta!

I've also got a c1969 Akai reel to reel tape machine, I still use that too..

Good man , it’s always good to see Darwin’s theories in practice , play on 

[melmerby]

40 minutes ago, Crosland said:

 

Sigh.

 

RCD is a very specific term. An RCD is always an RCD.

 

An RCBO is more than just an RCD. An RCBO is generally found in the consumer unit and include the breaker (i.e. cuts the power on an overload) as well as RCD function.

 

A thirteen Amp RCD would be very, very dangerous. I will leave you to do the research to understand why RCDs are rated in milliAmps. Do let us know what you find out.

ELCB was the term when I was at work in the 1980/90s, I helped wiring up work benches, which also had a panic button connected from line to ground via a suitable resistance to immediately cut the power.

Never quite saw the logic of that, surely if a fault has occured the device should have tripped long before anyone reached the panic button?

 

There was also a bleed resistance in circuit already passing IIRC 15ma so to trip would theoretically only need another 15mA.

Personally I was concerned how the integrity of the device would be affected by constantly passing a non tripping leakage current through it

 

These arrangements came from on high from our research department and were meant to be safer than the BS so couldn't be questioned!

Edited September 20, 2019 by melmerby

[melmerby]

I've got two of the H&M resistance controllers (not the complete power supply) which were available as an extra so you could build them into your control panel.

I also seem to remember you could buy different resistance mats for them, to allow for different current rated motors.

The ones I have worked fine with HD & Triang locos but are totally useless for modern locos as as soon as they are off the zero point the loco is going flat out!

 

EDIT

Just looked them out. They are H&M CUI/LC and the resistance is 50ohms.

IIRC they were not meant to be connected across the 12/15v DC and used as a potentiometer, only as an adjustable series resistance. There are only two connections to the resistance itself, a wire and the slider.

 

15v across 50 ohms would dissipate a lot of heat! (4.5W)

Edited September 20, 2019 by melmerby

[AndyID]

Small currents passing through the body may not be fatal but they can cause involuntary muscle contraction that prevents the victim letting go of the "hot" conductor. The panic button allows someone else to stop the current.

[maico]

There is a H&M Duette cover removal video on the tube

 

 

[BoD]

2 hours ago, Crosland said:

That's right. Anything flowing through the live must be balanced by the return through the neutral.

 

So why do I have to pay for it then?

[Porkscratching]

2 hours ago, Junctionmad said:

Good man , it’s always good to see Darwin’s theories in practice , play on 

Natural selection seems to have favoured me for 6 decades odd, including having quite a few belts off the mains in my time and sundry other incidents too numerous to mention, maybe it's a generational thing eh..

[Crosland]

1 hour ago, BoD said:

 

So why do I have to pay for it then?

 

Because you don't send it back in a fit state to be used again

 

[Bernard Lamb]

22 hours ago, Porkscratching said:

I've 'done' fuses with a bit off a nail too..

Needless to say I also won't be taking the advice of the bloke earlier to not use my old H&M transformers, they work for my purposes ta!

I've also got a c1969 Akai reel to reel tape machine, I still use that too..

That remark shows great dis-respect to an earlier poster who provided me with useful information.

If you continue in that manner don't expect me to send flowers to your funeral.

Bernard

[AndyID]

1 hour ago, Bernard Lamb said:

That remark shows great dis-respect to an earlier poster who provided me with useful information.

If you continue in that manner don't expect me to send flowers to your funeral.

Bernard

 

That's if there's anything left to bury.

[PatB]

50 minutes ago, AndyID said:

 

That's if there's anything left to bury.

Traditionally there will, at least, be a pair of slightly charred shoes. 

[Dava]

Quote

 

 

This is obviously the place for electrical advice. What happens if I plug residual Canadian 110v electricals into the UK mains? There is a  50w soldering iron I was going to run through  a  lamp dimmer and a food blender. Just asking. 

[AndyID]

27 minutes ago, Dava said:

 

This is obviously the place for electrical advice. What happens if I plug residual Canadian 110v electricals into the UK mains? There is a  50w soldering iron I was going to run through  a  lamp dimmer and a food blender. Just asking. 

 

Under NO CIRCUMSTANCES (sorry about the caps) do that. Your 50W iron will attempt to generate 200 watts. Hopefully it will explode before any real damage is done.

[Porkscratching]

Blimey I'm surprised that some folks are brave enough to even leave the house in the morning ... 

..you might even get hit by a piece of space debris...

[AndyID]

We can only hope.

[Porkscratching]

It only happens to nice people..

[Dava]

11 minutes ago, AndyID said:

 

Under NO CIRCUMSTANCES (sorry about the caps) do that. Your 50W iron will attempt to generate 200 watts. Hopefully it will explode before any real damage is done.

 

Thanks for the wise advice. It is a cheap Chinese iron so best not to try.

 

I'll revert to Plan B which is to convert my old Mamod stationary engine boiler into a whisky still. I plan to distil home-brewed beer. Should be OK if I silver-solder the joints in the copper pipes to avoid lead contamination. 

 

We Brits will have to be resourceful the way this Br***t nonsense is shaping up. 

[AndyID]

4 minutes ago, Dava said:

 

I'll revert to Plan B which is to convert my old Mamod stationary engine boiler into a whisky still. I plan to distil home-brewed beer.

 

Sounds like good plan. Just don't let the Customs and Excise find out about it.

 

Oops!

[kevinlms]

8 hours ago, melmerby said:

I've got two of the H&M resistance controllers (not the complete power supply) which were available as an extra so you could build them into your control panel.

I also seem to remember you could buy different resistance mats for them, to allow for different current rated motors.

The ones I have worked fine with HD & Triang locos but are totally useless for modern locos as as soon as they are off the zero point the loco is going flat out!

 

EDIT

Just looked them out. They are H&M CUI/LC and the resistance is 50ohms.

IIRC they were not meant to be connected across the 12/15v DC and used as a potentiometer, only as an adjustable series resistance. There are only two connections to the resistance itself, a wire and the slider.

 

15v across 50 ohms would dissipate a lot of heat! (4.5W)

Almost.

 

It can't be 50 Ohms. H&M according to my catalogue, made the resistance mats in 6 values.

 

Extra High (Resistance) for motors below 0.15 amps = 80 Ohms

High (Resistance) for motors 0.15 - 0.3 amps = 60 Ohms

Medium (Resistance) for motors 0.3 - 0.5 amps = 40 Ohms  This was the standard version and was factory fitted. You could get it replaced for another current range, for free within 7 days, or buy alternatives at any time.

Low (Resistance) for motors 0.5 - 0.75 amps = 30 Ohms

Extra Low (Resistance) for motors 0.75 - 1,5 amps = 20 Ohms

Heavy Current (Resistance) for motors 1,5 - 3 amps = 10 Ohms

 

The CUI/CL additional units used exactly the same mats, with the same choice.

 

Two things seem to be of note, your units must be of the standard Medium 60 Ohm Resistance or lower.

 

But those (Porkscratching?) who claim they get good control, probably have versions with higher resistance mats. Certainly these would perform much better on modern low current motors, than lower resistance models. This is why some people say they are 'good' controllers and others that they are 'useless'.

 

I've asked this question before, but no one seems to know what value their resistance mat is, they don't appear to be marked, so the only way to find out for sure, is by dismantling the cover and measure it (or have a CUI).

 

Moral of the story, not all H&M controllers are the same, even if they look identical.

[kevinlms]

On 15/09/2019 at 17:42, AndyID said:

 

Hi Bernard,

 

There were several versions of the H&M Powermaster. The earlier versions most likely used selenium rectifiers. It's not impossible that the later versions employed silicon rectifiers but I really don't know.

 

Even if it has selenium rectifiers and you are only using it very occasionally the risk of the rectifiers going south and causing injury is very small. The more important thing is that you are aware that there could possibly be a problem and you vacate the area at the slightest sign of trouble. And, as others have correctly pointed out there are potential issues with old electrical equipment quite apart from the rectifiers.

 

If you prefer to minimize all risks it's probably best to dump it.

 

Andy

 

 

There is a note in the Railway Modeller for 1958 November issue, that states the the Powermaster sold 10,000 units in the first 12 months of release. Don't know about the Duette, but I would guess they sold more units, because you could control 2 trains, compared to the Powermaster.