Old mem mcb type

[graham123]

Hi all, anybody come across these mem mcbs. Don't know what type they are. All it has on them is 3871 part 1. Apologies for the picture will upload a better one tommorow. cannot even find anything on Google or eBay.

 

[stefan]

correct you bow down pal

 

[frontier219]

no what im saying is they are prity old have a look at 15th edition and see what types there was you might take an educated guess as you seem to know what your talking about generally type 2 was used unless a special install ie a motor circuit then i would of not commented cheers

Nice to see an 'educated' guess when the OP has already pointed out that the circuit involved may have a high Zs. Lucky that wouldn't be in any way hazardous!

 

[frontier219]

no what im saying is they are prity old have a look at 15th edition and see what types there was you might take an educated guess as you seem to know what your talking about generally type 2 was used unless a special install ie a motor circuit then i would of not commented cheers

Out of interest, are your EICRs that thorough? I wouldn't want to go through such meticulous paperwork, it sounds like hard work.

 

[Leesparkykent]

correct you bow down pal

here you go.

 

[stefan]

what you getting at ?thats what ive said type 2 common like type B are now high zs is fine with theses look it up type B whats the max zs type c whats the max zs same as type 1 and type 2 different values today high zs i would use a type B yes are you understanding not a type c
when these mcbs in the photo were made there was the same type 2 common type 1 not common

 

[stefan]

yes ive got 25 years on the job

 

[spark 68]

what you getting at ?thats what ive said type 2 common like type B are now high zs is fine with theses look it up type B whats the max zs type c whats the max zs same as type 1 and type 2 different values today high zs i would use a type B yes are you understanding not a type c
when these mcbs in the photo were made there was the same type 2 common type 1 not common

No they are not the same at all

Type 1 are X4 In, Type B are X5 In
Type 2 are X7 In, Type C are X10 In
Type 3 are X10 In Type D are X20 In
Type 4 can be various depending on manufacturer

If anything Type 3 are roughly equivalent to type C

 

[Leesparkykent]

yes ive got 25 years on the job

Cool!!

 

[frontier219]

yes ive got 25 years on the job

And for how many of those years have you been complacent in recording circuit details?

 

[Charlie_]

Type 1 were actually the most common as they were classed as resistive mcb's..

pop quiz... No cheating! Googling or whatever your preferred cheat is!
we have mentioned types b,c & d but not type a.
why are type a MCBs so special??? No cheating!

 

[Leesparkykent]

Type 1 were actually the most common as they were classed as resistive mcb's..

pop quiz... No cheating! Googling or whatever your preferred cheat is!
we have mentioned types b,c & d but not type a.
why are type a MCBs so special??? No cheating!

well I don't know and not going to cheat either lol.

 

[stefan]

OK so do ya want a gold medal

 

[frontier219]

Type 1 were actually the most common as they were classed as resistive mcb's..

pop quiz... No cheating! Googling or whatever your preferred cheat is!
we have mentioned types b,c & d but not type a.
why are type a MCBs so special??? No cheating!

Genuinely didn't know they existed! Do tell, I'm intrigued.

 

[Leesparkykent]

OK so do ya want a gold medal

Jog on mate you are getting boring!

 

[Charlie_]

Haha I said what's special about them?
trick question... They don't exist...
the reason why, is because when they done away with the old codes in the 90's
the powers that be didn't want the type getting confused with the current rating A..

 

[stefan]

You challenge my comment I put my opinion across type 2 if you don't like it that's up to you how much experience have you in this field think you should go on the diy forum

 

[spark 68]

No they are not the same at all

Type 1 are X4 In, Type B are X5 In
Type 2 are X7 In, Type C are X10 In
Type 3 are X10 In Type D are X20 In
Type 4 can be various depending on manufacturer

If anything Type 3 are roughly equivalent to type C

Actually this is not strictly true, the types B,C and D have a range of magnetic trip currents, which extend to the letter below, Type B = 3 to 5 X In, Type C = 5 to 10 X In, and Type D = 10 to 20 X In, just we use the highest number multiplier as the worst case.

The older standard has a different range which I would need to look up the numbers quoted for Types 1 to 3 are the worst case for that standard, which is all I am really bothered about anyway

I have no idea about Type A, I don't even know if they exist or not lol

 

[frontier219]

You challenge my comment I put my opinion across type 2 if you don't like it that's up to you how much experience have you in this field think you should go on the diy forum

If you're not a troll then I despair for your customers. 'Type 2' is not your informed opinion through your years of knowledge. It is an uneducated guess based on the flimsiest of conclusions.

 

[stefan]

OK what ever

 

[Charlie_]

Type 1..2.7 - 4In
Type 2..4 - 7In
Type 3..7-10In
Type 4...10 - 50In

 

[spark 68]

Type 1..2.7 - 4In
Type 2..4 - 7In
Type 3..7-10In
Type 4...10 - 50In

Cheers Charlie, I have the curves and other data on this computer somewhere, plus a copy of the 15th Ed.

 

[stefan]

Glad someone finally knows what their talking about thank God

 

[Knobhead]

Hi all, anybody come across these mem mcbs. Don't know what type they are. All it has on them is 3871 part 1. Apologies for the picture will upload a better one tommorow. cannot even find anything on Google or eBay.

Didn't look very hard did you.

 

[graham123]

@tony If you could point me in the right direction Tony on the Internet that would be great!

 

[Knobhead]

Google!