Today`s I&T job

[kme]

A local AirCon company have the contract for the courts - and just installed a couple of units in a courthouse. They need NIC certs, so asked if I`d go do the I&T for them.

Now, I know what I think about the following - but I`d like to see what y`all think of a couple of things.

The existing installation is PME - they`ve come off a TPN sub-board, (supplied from MCCB@60A/phase)

They`ve installed 2 runs of 5 core SWA - approx 10 metres, and 14 metres respectively.

The runs are to 32A isolators; located directly behind the condensing units - awkward to switch on/off; a damn nightmare to open for testing.

The SWA is then taken from the iso to the condenser unit.

The units are rated 19A per phase each.

The sub board they`ve used is a 12 way TP (type B) ; with these loads already installed:

5 lighting circuits - each on a 10A MCB

1 single phase sub-main, to an unknown location, on a 50A MCB

2 radial socket circuits - each on a 16A MCB

3 ring circuits - each on a 32A MCB

2 SP aircon units, each on a 32A MCB

1 hand dryers circuit - 32A

2 circuits, each with 2 hand dryers on a 20A MCB

1 no. water heater on a 20A MCB and

3 no. water heaters, each on a 16A radial.

The banjos have not been fitted on the DB end.

The glands on the isolators are 20Bs, not Cs.

Oh, and the DB is a merlin (with a mix of merlin and schneider MCBs and RCBos) - the aircon co. have used schneider C32A TPN MCBs

Anybody else foresee a problem???

opcorn

 

[SLIPSHOD & SLAPDASH]

Aside from the overloaded board, What size SWA cable ? Air con guys always seem to underate cables. Merlin Gerin is now Schenider.

 

[Evans Electric]

Can you see something we can't then Martyn?

I tend not to panic over hand driers too much , they're very short term operation , water heaters are often off more than they are on . A reading on the mains to the board would be in order , doesn't look too desperate to me TBH .

The new Air cond will make a difference of course.

Whats affecting your radar ?

 

[steptoe]

well, apart from a loading issue

50A SP sub to somewhere ?????

Im guessing they have used small cable to get it to fit a 20 Gland if its 5core.

 

[Evans Electric]

I also find all the waffle about different makes of MCB in boards has an amount of scaremongering about it , if it fits properly then it fits . An appropriate means of protection has been fitted between the board and the sub-main, correct rating ,correct type,correct BS etc.

 

[Manator]

I see something, that I think KME is pointing to and it has nothing to do with different makes of mcb's.

 

[kme]

Sorry, forgot to include cable size:

6mm XLPE.

Deke - yeeeees; it all tags out - 25mm submain; cables protected etc. I don`t know if it was the idiocy of plonking the iso`s right behind the condensers, or the glanding, or just me over-looking for problems.

Looking at it again is out of the question - we`re only allowed in the building after court hours, and have to have a G4S bod shadowing us, with one hand constantly on his weapon, in case we try to steal the courthouse or summat - FFS!!!

Herein lies the issue - clamping the tails showed a 10A load - but that was 5.30 tonight, with no-one in the building. I can`t clamp it during "normal" operating times.

So I may have been over-reacting to the loading issue - but the two units will load up 66% of the capacity, if they`re starting together....(.IF the rating plate is inrush peak) ; rather than running current,

Otherwise, the duty cycle of 38A/phase going to these 2 units is much higher - plus the other two AC units (unaccessible), plus the unknown load on the sub (10mm, 50A).

Basically, I have concerns that they`ll take out the moulded case mate........

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edit: Following Manator`s comment: I think its a case of - looking at the way things have been done in general - am I happy to sign I&T? I don`t like the lack of armour earth continuity - but they DO have an earthed core - and the readings are acceptable.

 

[Marvo]

If you suspect that the maximum demand exceeds the supply capability we would usually just warn the client in writing to avoid any bad feeling after the installation work is complete. We don't really consider tripping the MCCB or ACB because of demand as a fault as such, more as a business opportunity to sell them a range of energy saving techniques .

 

[wozz]

Are you saying the armour isn't earthed? I assume a metal TP board so can't understand how it hasn't been earthed?

---------- Post Auto-Merged at 07:58 ---------- Previous post was made at 07:56 ----------

Are the company happy to sign the relavent parts of test cert?

 

[ProDave]

Is it just me?

A company takes on a large install in a court house. BUT they don't have the trained personnel in house to sign the job off. WTF? headbang headbang headbang

And, there's no such thing as an "NIC Certificate" Legally there are EIC, MCW's etc but the regs do not recognise specific scam operators variants of them. An EIC from ANYONE should be sufficient.

I hope you are using a 3 signature EIC and only signing the inspection part, and leaving the original contractor to sign the design and construction sections.

 

[Sidewinder]

A local AirCon company have the contract for the courts - and just installed a couple of units in a courthouse. They need NIC certs, so asked if I`d go do the I&T for them.Now, I know what I think about the following - but I`d like to see what y`all think of a couple of things.

The existing installation is PME - they`ve come off a TPN sub-board, (supplied from MCCB@60A/phase)

They`ve installed 2 runs of 5 core SWA - approx 10 metres, and 14 metres respectively.

The runs are to 32A isolators; located directly behind the condensing units - awkward to switch on/off; a damn nightmare to open for testing.

The SWA is then taken from the iso to the condenser unit.

The units are rated 19A per phase each.

The sub board they`ve used is a 12 way TP (type B) ; with these loads already installed:

5 lighting circuits - each on a 10A MCB

1 single phase sub-main, to an unknown location, on a 50A MCB

2 radial socket circuits - each on a 16A MCB

3 ring circuits - each on a 32A MCB

2 SP aircon units, each on a 32A MCB

1 hand dryers circuit - 32A

2 circuits, each with 2 hand dryers on a 20A MCB

1 no. water heater on a 20A MCB and

3 no. water heaters, each on a 16A radial.

The banjos have not been fitted on the DB end.

The glands on the isolators are 20Bs, not Cs.

Oh, and the DB is a merlin (with a mix of merlin and schneider MCBs and RCBos) - the aircon co. have used schneider C32A TPN MCBs

Anybody else foresee a problem???

opcorn

No issues with the mcb mixing as they are not mixed, Schneider have issued a memo to this affect.

Are they suitably rated?

I would not be happy without the armour reliably earthed at the supply end.

If the isolators are polymer rotary then I would not be happy if the armour is clamped tight to the plastic and in through the top as the polymer will migrate. I'm guessing exterior due to the bw/cw comment?

Bonding for the air-con system?

Why 32A mcb's for a 19A load?

I would guesstimate with diversity that you should be OK for total load if it is well balanced.

What does the volt drop calc out at in comparison with manuf' & 7671 requirements?

 

[kme]

Is it just me?A company takes on a large install in a court house. BUT they don't have the trained personnel in house to sign the job off. WTF? headbang headbang headbang

And, there's no such thing as an "NIC Certificate" Legally there are EIC, MCW's etc but the regs do not recognise specific scam operators variants of them. An EIC from ANYONE should be sufficient.

I hope you are using a 3 signature EIC and only signing the inspection part, and leaving the original contractor to sign the design and construction sections.

Of course mate - and sorry for my shorthand; it was late & a long day.

No issues with the mcb mixing as they are not mixed, Schneider have issued a memo to this affect.Are they suitably rated?

I would not be happy without the armour reliably earthed at the supply end.

If the isolators are polymer rotary then I would not be happy if the armour is clamped tight to the plastic and in through the top as the polymer will migrate. I'm guessing exterior due to the bw/cw comment?

Bonding for the air-con system?

Why 32A mcb's for a 19A load?

I would guesstimate with diversity that you should be OK for total load if it is well balanced.

What does the volt drop calc out at in comparison with manuf' & 7671 requirements?

At the DB, the glands are bolted to the steel; banjo on the outside, but unused.

At the poly iso, glands in/out at the bottom; banjos again external - might be fixed together, but can`t see, due to location!!!

Bonding fitted to pipework mate.

Don`t have manufacturers data for v.d. Haven`t calced it yet....too late last night.

Why 32s? I don`t have a scooby.

 

[Sidewinder]

At the poly iso, glands in/out at the bottom; banjos again external - might be fixed together, but can`t see, due to location!!!

Could be a designers breach of CDM there then, how will the end user comply with PUWER98?...

If the iso's are that inaccessible, then that could be an issue.

Not only CDM, but also the MHSWR.

Trust me you don't want a non compliant install for the Department of Justice!

They were not best pleased when I EDN'd a brand new install of theirs & issued a report citing about 20 breaches of CDM & PUWER98!

 

[kme]

Thanks.

THAT was the bit of info I was looking for - The SWA`s pass muster on testing....but I REALLY wasn`t happy with their location - just wanted to clarify the position. Think I need to talk to the A/C company - let them know "unofficially", and see what they want to do.

 

[Sidewinder]

KME,

IF I can make the time I'll call down with you if you "have" the job!

I also have links with the DOJ, I was with the guy who does all the Court cell locks last week!

 

[Manator]

I was with the guy who does all the Court cell locks last week!

So that's how you got out

:slap

 

[Sidewinder]

Shh!

For goodness sakes don't tell everyone!

I'm back in prison soon enough.

 

[Manator]

Yea I think we are doing one soon, I do not mind most jobs but I hate the prisons!!!