Spd on Eaton Tpn

[cliffed]

just been handed this to fit to a TPN DB,have you seen anything so ridiculous,it’s a SPD, those cables are so short,

 

[pc1966]

I think they are supposed to be mounted on the side of the DB, closest to the main switch, via a high current breaker (32A or more D-curve, etc) or in some cases just joining blocks. Not sure if there are any punch-out holes or you are expected to drill something.

The short cables are needed to keep the inductance down as lighting surges are only tens of microseconds long and so L usually dominates of R in most cases. A quick look in the 18th regs has max 1m but preferred less than 0.5m total wiring, so 2 * 25cm to the SPD.

Same reason for going for a MCB with a high magnetic trip point - less of a coil for that so lower series inductance.

 

[Strima]

As above, it's designed to fit onto the side of the DB.

 

[davesparks]

just been handed this to fit to a TPN DB,have you seen anything so ridiculous,it’s a SPD, those cables are so short,

Yes, the cables must be kept as short as possible, if you make them much longer than that then the SPD won't work properly.

Those cables will be exactly the right length to fit the device where the manufacturer specifies that it goes.

 

[cliffed]

Cheers,this is an add on to existing Tpn,where it’s impossible to mount with those connections,to the side of the TPN.
Bearing in mind the max distances,possible to connect @ 1m max with 16mm ,mcb rated @ 63 amp.

 

[davesparks]

Cheers,this is an add on to existing Tpn,where it’s impossible to mount with those connections,to the side of the TPN.
Bearing in mind the max distances,possible to connect @ 1m max with 16mm ,mcb rated @ 63 amp.

You'll need to speak to Eaton technical support, only they can tell you what is acceptable for their SPD.

 

[cliffed]

You'll need to speak to Eaton technical support, only they can tell you what is acceptable for their SPD.

Will do,cheers...this is what happens when no thought’s are used when ordering/fitting this unit