air con units in a steel shipping container.

[BertUK]

hi,im about to embark on installing some power in a steel shipping container,im going to use a Schneider 6 way board rcd main switch.there are 2 air con units going in here but onlt one will be running at any one time,the other is purely as a back up if one fails, both rated at 5kw cooling and 5.8 kw heating.im thinking about running 2 x 4mm t+e to 2 x switched fused spurs protected by 20a mcb,s at the board.is there a better way or easier way?.

 

[Plonker 3]

Well seeing as they are both rated at 25 amps, you need to rethink the OCPD and maybe cable size, then use a rotary isolator or 32A DP switch.

 

[BertUK]

Well seeing as they are both rated at 25 amps, you need to rethink the OCPD and maybe cable size, then use a rotary isolator or 32A DP switch.

why do I need to re-think the cable size?

 

[Plonker 3]

I said maybe depending on CCC and volt drop etc, not got my books with me right now to check CCC.

 

[BertUK]

4mm clipped direct has a current rating of 37 amps so a 20a or 32a ocpd would suffice if im not mistaken?

 

[Plonker 3]

Well 32 amp OCPD as the FLC is over 25A

 

[shanky887614]

6kw is about 26amps

 

[Plonker 3]

I also wouldnt put these on a DB with a RCD switch, seperate RCBOs in the DB if the circuits need protecting.

 

[BertUK]

I also wouldnt put these on a DB with a RCD switch, seperate RCBOs in the DB if the circuits need protecting.

whats the reason,theres 2 water tank heaters and 2 air con units and 1 light circuit,its in a quarry and not the end of the world if the rcd trips.

 

[BertUK]

whats the reason,theres 2 water tank heaters and 2 air con units and 1 light circuit,its in a quarry and not the end of the world if the rcd trips.

I guess there isn't one!

 

[Plonker 3]

I guess there isn't one!

Sorry I didnt realise that I had to respond to any question instantly.

 

[BertUK]

that wasn't aimed at you, it wouldn't be cost effective anyway for me to use them as one of the rcbo,s would effectively be turned off permanently.

 

[Hawkmoon]

May not be the end of the world but it would be nice to still have the lighting if one of the ac units trip

 

[Hawkmoon]

that wasn't aimed at you, it wouldn't be cost effective anyway for me to use them as one of the rcbo,s would effectively be turned off permanently.

You could use one feed with a changeover arrangement

 

[ian.settle1]

whats the reason,theres 2 water tank heaters and 2 air con units and 1 light circuit,its in a quarry and not the end of the world if the rcd trips.

If it is in a quarry I would check to see if there are any other regulations you need to adhere to besides BS7671

Like the Quarry regulations 1999

 

[BertUK]

I have thought it through and it DOES all come down to costing,there is only ever anyone going to go in this container in daylight hours so the lights are there,just to be there.this is why ive gone for an rcd main as opposed to seperates.

 

[BertUK]

If it is in a quarry I would check to see if there are any other regulations you need to adhere to besides BS7671

already checked and there isn't any,as long as the zs,s are met and everything is to bs7671 then its ok.

 

[Hawkmoon]

Don't your guys work after 4 in the winter then? bloody part timers

 

[BertUK]

Don't your guys work after 4 in the winter then? bloody part timers

its the concrete testing side of the quarry,this container is purely for putting concrete samples into water tanks and leaving them to soak for a week before crush testing them.

 

[Engineer54]

What type of AC units are we talking about, wall bangers or split units?? To be totally honest, AC units are probably one of the most reliable bits of kit you can buy these day's, and often come with 3 or 5 year guarantees. So pretty pointless installing two unit's when only one is required!!