Alberta codes...are they crazy or am i ?

[pawketz]

i write for my master's ticket on monday and i'm having a problem with something the NAIT pre-test is trying to tell me.

It says that when you do the load calculation for the suites in an apartment calculation, even though the service is 120 / 208 3phase 4 wire your supposed to calculate the amperage draw at the suites at 240 volts.

Now maybe there is some rule that i don't know about, but in all my years of being an electrician i've never been able to get 240 volts out of a 208 system just because i want to.

Hopefully someone can help me out...like i said i'm having a real problem with this....and of course do you think that the guys from NAIT are returning my phone calls abou this? Of course not, they already have my money..why should they care

( can you tell i'm a bit stressed out over this )

Anyways, thanks for your help in advance.

pawketz

[bigrockk]

Hello pawketz,
N.A.I.T. is not steering you wrong,this comes
from the STANDATA Rule 8-100

The following is quoted directly from the Standata,I assume you have a copy so you can check it out for yourself.

Rule 8-100 Current Calculations
120/208 V, 3-wire feeders from a 120/208 V, 3 phase, 4-wire supply
To obtain the voltage divisor for calculating the minimum ampacity of 120/208 V, 3-wire
feeders, use the voltage between a phase and the identified conductor (120V) multiplied by two
(120 x 2 = 240V).
The voltage divisor for calculating the minimum ampacity of the 120/208 V, 3-phase, 4-wire
service conductors is, of course, 1.73 x 208 V.

I successfully wrote the Master's two and a half years ago, at that time it was a seven hour exam,write for 3.5 hours,then a 1 hour break for lunch and then 3.5 more hours of exam writing.I assume its still the same so, about the best advise I can give you is RELAX as much as you can...its a long day.
When you recieve your exam do some of the easier questions first just to put yourself at ease and to get yourself thinking electrically,it helps.

Best of luck!!!!!

<font color="#a62a2a" size="1">[ July 05, 2003 10:19 PM: Message edited by: bigrockk ]</font>

[bigrockk]

Hey pawketz,
Just wondering how the exam went for you??