3 phase help.

[lamb]

thanks mate. i only av to supply up to the rotary switch.iv got 16mm cable 4 core ans seperate 16mm earth wire. we bought 16mm as we were gona put a 3 phase board as the owner also wanted a 3 phase chiller. so my cable is too big but who cares, im not paying 4 it. tanx. wat tests will i need to do on that install

Check rating and condition of existing equipment including that of the distributor to confirm it is suitable for the additional load. Check adequacy of existing earthing and bonding arrangements, upgrade if not adequate.

Test R1+R2 of the new circuit, insulation resistance between all conductors, and confirm polarity.
Energise circuit, and immediately confirm polarity and verify phase sequence.
Measure Zdb at the distribution board for your circuit, add this to the R1R2 to calculate Zs.
At DB, measure PEFC. Measure PSSC and multiply this by square root of 3 to calculate prospective three phase fault current. Verify your breaker is adequately rated for this.
Verify voltage drop between origin of installation and the isolator you have installed with the load connected.
Complete and sign the Electrical Installation Certificate.

 

[m25maintenance]

seems ur all enjoying the funny answers but hey i dont care. we had to start at the begining. mate the company supplying the oven will do all work after the rotary switch. the company asked for a 3p and n supply.

R1+R2 and Ir mate, only IR to the rotary switch and im afraid you have absolutely no chance of getting 16mm 4 core terminated in the oven, i would buy a 3mtr length of 6mm for that!

I hate to keep asking but who is commisioning the oven ?? because these things need setting up by the installer on first power up, and involve all sorts of set up and calibration, i know on the far superior Rationals it takes about a hour and thats if you know what you are doing!

What size breaker do you have for this and what type is it??

Also the cable from rotary to oven will need to be 5 core as there is absolutely no way of terminateing a seperate earth to these ovens! having said that most ove these ovens are 3ph only and do not require Neuteral, if this is the case do away with the 16mm supp earth, and use the 4th core as cpc, again all of this needs confirming before arrival on site

 

[High Tower]

seems ur all enjoying the funny answers but hey i dont care. we had to start at the begining. mate the company supplying the oven will do all work after the rotary switch. the company asked for a 3p and n supply.

U aint got a problem if u aint gotta connect the unit up!

Its a simple circuit then, and good news about the commisioning as its a nightmare!!

Make sure that you use a type c breaker as these things dont half pull on start up and as you are using massively oversized cable then make sure the breaker is the right size(20a) so you are de-rating the circuit

 

[m25maintenance]

tanx mate.happy monday comming i hope.

U aint got a problem if u aint gotta connect the unit up!

Its a simple circuit then, and good news about the commisioning as its a nightmare!!

Make sure that you use a type c breaker as these things dont half pull on start up and as you are using massively oversized cable then make sure the breaker is the right size(20a) so you are de-rating the circuit

 

[m25maintenance]

just one thing i dont understand here. why is one guy saying 20a breaker and othere saying 45 and 50

 

[High Tower]

caus u origanally stated 3x33 amp supply and these little ovens are no where near that mate

 

[m25maintenance]

ok but thats the info the oven supplier sent me. ill put the cable and rotary switch in and wait 4 more info

caus u origanally stated 3x33 amp supply and these little ovens are no where near that mate

 

[m25maintenance]

ok but thats the info the oven supplier sent me. ill put the cable and rotary switch in and wait 4 more info

also how do get to the 20 amp . wats d calc

 

[ringer]

Check rating and condition of existing equipment including that of the distributor to confirm it is suitable for the additional load. Check adequacy of existing earthing and bonding arrangements, upgrade if not adequate.

Test R1+R2 of the new circuit, insulation resistance between all conductors, and confirm polarity.
Energise circuit, and immediately confirm polarity and verify phase sequence.
Measure Zdb at the distribution board for your circuit, add this to the R1R2 to calculate Zs.
At DB, measure PEFC. Measure PSSC and multiply this by square root of 3 to calculate prospective three phase fault current. Verify your breaker is adequately rated for this.
Verify voltage drop between origin of installation and the isolator you have installed with the load connected.
Complete and sign the Electrical Installation Certificate.

Don't understand the references to checking polarity, unless you mean ensure the neutral supply wire and not a live wire is put into the neutral terminal in the rotary switch, but then I know practically nothing about three-phase. And I can understand the test for correct phase sequencing in a 3ph motor - but will the three phases be split inside the oven, one for each module (boiler, oven 1, oven2), or do 3ph ovens work differently to that?

 

[High Tower]

To be honnest im at work and havent had time to do calcs, just we have the bigger brother the 10g 1/1 and i went and had a look as to what that is on

 

[davelerave]

don't know much but the majority of the load is a 9kw boiler-that may well be a 3*3KW star -connected load


any fans may be single phase so rotation is prob not an issue here

neutral is a 'live' wire btw