Electricial certification Question
Jun 5th 2011, 2:47 pm
#16
Account Closed
Joined: Nov 2009
Posts: 183
Re: Electricial certification Question
That's good news for you, even if there is a problem, I think you could just simply sit the Provincial exam for a Journeyman electrician and work in the province where you live. Then sit the red seal later on if you needed to.
This might be of interest to you with regards to a few basic common terminology and methods that you will come across.
Live = hot
RCD = GFCI ground fault circuit interuptor 6ma instead of 30ma.
Earth/cpc = bond wire non sleeved, but sometimes seen with green sleeving.
Polarity on sockets is such that if the position of the socket is horizontal, then the hot pin receptor shall be underneath the neutral, to prevent a knife or such being dropped and landing between the plug and socket and causing live contact to the knife. But I have noticed that the ground pin is always below when sockets are mounted verticle?
Cable calculations tend to on an average 20% decrease with 4 or more bunching, haven't found correction factor formulae for further calculation as yet.
Twin and earth = romex or loomex.
Conduit and other raceway sizes are metric but vary a couple of mil with the sizes over here, so your stocks and dies won't be of much use, but maybe the stocks might take the dies.
There are 2 types of metal conduit, one type is thick walled and can be threaded, and is sometimes formed with a bender that consists of a former with a long bar screwed into it. Then all the forming is done form the floor with the tube always being bent upwards. On larger projects, hydraulic benders are common.
The other is just cut and joined and branched with accessories similiar to pvc ones, but are clamped with locking screws and are better being treat like pvc with regards to earth continuity!
Cable sizes are still in AWG, and ally conductors are sometimes used but are to be the next size up for the same current rating as copper conductors. But can't be used on fire alarm circuits. Screwitts/maurette wire nuts are still used for jointing and terminating, even inside outlet box's.
RYB, Bla N/Br,Bla,Gy Blu N = R,Bla,Blu, Whi N occasionally grey. Black and white colours used on single phase circuits, black being hot! not neutral.
1 way switch = 2 way
2 way = 3 way
Intermediate = 4 way
50 v elv = 30 elv
Dist board = panel board
Industrial voltage is typically 60 hz 480v to earth and 277v for discharge lighting, and other voltages are also found in certain applications.
Domestic/residential supplies are 60 hz 120v phase a + 120v phase b = 240v used where 2kw or greater loads are connected, 208v is found at panel boards when probing phase a or b to neutral (120 x root 3), depending on the configuration on the service tranny. But I've never seen appliances rated for that voltage, so I'm not too sure why its actually there.
I think its used as a temporary method for 240 volt loads when there is a problem with the supply service and one of the tranny windings is burnt out. Then the 240v loads are reconfigured in the panel board, and sometimes by the lines men up the pole if they need to shift the connections around. But don't quote me on it as I haven't found that one out as yet, I'm still studying it myself.
When you get further towards getting over there it might be wise to purchase the CEC from the CSA website along with the handbook for it package (22.1 09). You will probably be better off studying the code first then refer to the guide when you need to, as I found it a bit misleading as its not like the on site guide we have in the UK. The CEC and handbook are sold as a package, although I think its only available in CD rom now.
Good luck with your application.
This might be of interest to you with regards to a few basic common terminology and methods that you will come across.
Live = hot
RCD = GFCI ground fault circuit interuptor 6ma instead of 30ma.
Earth/cpc = bond wire non sleeved, but sometimes seen with green sleeving.
Polarity on sockets is such that if the position of the socket is horizontal, then the hot pin receptor shall be underneath the neutral, to prevent a knife or such being dropped and landing between the plug and socket and causing live contact to the knife. But I have noticed that the ground pin is always below when sockets are mounted verticle?
Cable calculations tend to on an average 20% decrease with 4 or more bunching, haven't found correction factor formulae for further calculation as yet.
Twin and earth = romex or loomex.
Conduit and other raceway sizes are metric but vary a couple of mil with the sizes over here, so your stocks and dies won't be of much use, but maybe the stocks might take the dies.
There are 2 types of metal conduit, one type is thick walled and can be threaded, and is sometimes formed with a bender that consists of a former with a long bar screwed into it. Then all the forming is done form the floor with the tube always being bent upwards. On larger projects, hydraulic benders are common.
The other is just cut and joined and branched with accessories similiar to pvc ones, but are clamped with locking screws and are better being treat like pvc with regards to earth continuity!
Cable sizes are still in AWG, and ally conductors are sometimes used but are to be the next size up for the same current rating as copper conductors. But can't be used on fire alarm circuits. Screwitts/maurette wire nuts are still used for jointing and terminating, even inside outlet box's.
RYB, Bla N/Br,Bla,Gy Blu N = R,Bla,Blu, Whi N occasionally grey. Black and white colours used on single phase circuits, black being hot! not neutral.
1 way switch = 2 way
2 way = 3 way
Intermediate = 4 way
50 v elv = 30 elv
Dist board = panel board
Industrial voltage is typically 60 hz 480v to earth and 277v for discharge lighting, and other voltages are also found in certain applications.
Domestic/residential supplies are 60 hz 120v phase a + 120v phase b = 240v used where 2kw or greater loads are connected, 208v is found at panel boards when probing phase a or b to neutral (120 x root 3), depending on the configuration on the service tranny. But I've never seen appliances rated for that voltage, so I'm not too sure why its actually there.
I think its used as a temporary method for 240 volt loads when there is a problem with the supply service and one of the tranny windings is burnt out. Then the 240v loads are reconfigured in the panel board, and sometimes by the lines men up the pole if they need to shift the connections around. But don't quote me on it as I haven't found that one out as yet, I'm still studying it myself.
When you get further towards getting over there it might be wise to purchase the CEC from the CSA website along with the handbook for it package (22.1 09). You will probably be better off studying the code first then refer to the guide when you need to, as I found it a bit misleading as its not like the on site guide we have in the UK. The CEC and handbook are sold as a package, although I think its only available in CD rom now.
Good luck with your application.
Jun 6th 2011, 9:07 pm
#17
Forum Regular
Thread Starter
Joined: May 2011
Posts: 40
Re: Electricial certification Question
thanx for that mojo found that really helpful . Ive been looking through net and not really found any helpful sites for that type of thing so appreciate u taking time to give me sum tips ! Yes ive ordered c22.9-1 code book and will recieve it wen im over there next week and hopefully will help me further ( still a little confused bout the diff voltages being used in domestic units and the phase a / b , is this so less current flows though the cable with heavier loads ? )
Also not sure about the 480v to earth for industrial voltage either
as with ours it is 415v between phases and 230v to earth !! Im sure things will be clearer wen i get my hands on my study books next week though ! just seems like so much different voltages are used .... 120,208,240,277,480 ! Uk alot easier to remember lol
thanx again
Also not sure about the 480v to earth for industrial voltage either
as with ours it is 415v between phases and 230v to earth !! Im sure things will be clearer wen i get my hands on my study books next week though ! just seems like so much different voltages are used .... 120,208,240,277,480 ! Uk alot easier to remember lolthanx again
Jun 6th 2011, 10:45 pm
#18
Account Closed
Joined: Nov 2009
Posts: 183
Re: Electricial certification Question
Sorry my mistake about 480 v to earth, its between phases. I think that the 120v supplies derive from the mid 19th century when there were no grid networks, and you had your own DC genny mainly for lighting, as there wasn't much else. In the UK it was the same set up, the voltages were similiar in range, then they moved towards higher voltages for higher powered loads. Eventually swinging between 200 to 300 volts, North America staying with the lower voltage of around 100 to 120v. Then eventually they moved over to AC when they found a use for it, supplying two out of three phases, a&b, b&c, or c&a, with a neutral to residential and commercial properties. Via a delta connected secondary with a centre tap between the windings giving 120v to earth, and 240v between phases a,b, or c., giving an ungrounded 240v supply. Very similiar to a 110v reduced low voltage system for control and power tools, giving 55v to earth when centre tapped, and 110v between the windings.
Digressing slightly
Until the late 40s, the voltage in the UK still varied between 200-250v, until they built the national grid. Certain regions had appliances and light bulbs rated at different voltages, if you bought a toaster or fire in say Manchester, it might not work as well or for as long in Newcastle, it might have burnt out quicker, or burn slightly dimmer. The grid system in North America isn't a national one like in the UK, due to the load demand being hit and miss across such a big area, unlike the UK. They still tend to have a handful of power stations supplying a smaller local grid network supplying a few cities, with not much, or no interconnection between the grids.
They have a distribution network of around 7.2 kv, feeding 45 kva trannies for each property. Unlike the 11kv fed subs supplying 100 or more properties like in the UK, they tend to be reserved for industrial and large commercial loads. And having multiple tappings, one tapping being reserved for the 277v discharge lighting. At the end of the day they are still trannies, except with more tappings due to the evolution and development of the load demand of North America. The pme connection is done by the sparky and not the area board, and is just a case of linking the neutral and ground bar out in the dist/panel board. But it must not be linked on any other sub main. Some of the older more rural properties are still fed with 120v to earth, single phase.
Digressing slightly
Until the late 40s, the voltage in the UK still varied between 200-250v, until they built the national grid. Certain regions had appliances and light bulbs rated at different voltages, if you bought a toaster or fire in say Manchester, it might not work as well or for as long in Newcastle, it might have burnt out quicker, or burn slightly dimmer. The grid system in North America isn't a national one like in the UK, due to the load demand being hit and miss across such a big area, unlike the UK. They still tend to have a handful of power stations supplying a smaller local grid network supplying a few cities, with not much, or no interconnection between the grids.
They have a distribution network of around 7.2 kv, feeding 45 kva trannies for each property. Unlike the 11kv fed subs supplying 100 or more properties like in the UK, they tend to be reserved for industrial and large commercial loads. And having multiple tappings, one tapping being reserved for the 277v discharge lighting. At the end of the day they are still trannies, except with more tappings due to the evolution and development of the load demand of North America. The pme connection is done by the sparky and not the area board, and is just a case of linking the neutral and ground bar out in the dist/panel board. But it must not be linked on any other sub main. Some of the older more rural properties are still fed with 120v to earth, single phase.
Jun 7th 2011, 9:28 pm
#19
Forum Regular
Thread Starter
Joined: May 2011
Posts: 40
Re: Electricial certification Question
ok thanx I get it now , yes gonna take a bit of getting used to but looking forward to the new challenges ahead ! cheers for all the great advice
