Mark @ Everlast
Advertiser
The PA 300 will work with that 3 phase power, and pull less amps. Use the red leg for the high leg (high voltage).
3 Phase?
- Thread starter DXN1EL
- Start date
- Views: 5575
buickanddeere
Super Member
I've been over, in and under 540, 750 and 860MW nuclear powered steam turbine generators and their support systems for 23yrs. As a Control Tech, Fire Captain and Radiation Protection Green Badge.
Tractor Seabee
Elite Member
- Joined
- Oct 5, 2011
- Messages
- 3,902
- Tractor
- Kubota BX25
In my recollection of past history what you have is what is called an open delta power distribution. This is a system very seldom used anymore. It was used by power companies to provide 3 phase power for motor loads where the distribution system in the area was single phase, like predominately residential areas. I first encountered this in Phoenix AZ back in the 50s when Air conditioning was becoming high demand in homes. That was their short term solution till revenue for more power paid for changing the distribution systems to three phase primary. At that time 3 phase compressor motors were half the price of single phase and were much more efficient, hence this solution.
Open delta is derived from single phase using only 2 transformers. The so called "wild leg" by code could only be used for the third phase (3rd conductor) of a motor circuit. That conductor had to be a unique color from all the others so it could be readily identified. The motor circuit could not be part of the distribution panel that was required to only single phase. We bus tapped the other two conductors in a gutter ahead of the panel to insure separation. It was a grossly unbalanced system electrically and raised havoc with the newly emerging TV sets and radios. A lot of these setups rapidly were overloaded as more AC units were added to that second transformer. The power company loaded them till they blew up and then replaced with a bigger one.
You probably will never see power companies doing this today. I looked into it once for a 15 HP motor and they said it was my problem to solve with an electrical contractor on my side (secondary). We did the open delta just for the motor. By the way the open delta provides only 60% of the power for the same KVA as a delta or Y connected transformer bank.
This is all recollection from my early years as an Air-conditioning technician in Phoenix.
Ron
Open delta is derived from single phase using only 2 transformers. The so called "wild leg" by code could only be used for the third phase (3rd conductor) of a motor circuit. That conductor had to be a unique color from all the others so it could be readily identified. The motor circuit could not be part of the distribution panel that was required to only single phase. We bus tapped the other two conductors in a gutter ahead of the panel to insure separation. It was a grossly unbalanced system electrically and raised havoc with the newly emerging TV sets and radios. A lot of these setups rapidly were overloaded as more AC units were added to that second transformer. The power company loaded them till they blew up and then replaced with a bigger one.
You probably will never see power companies doing this today. I looked into it once for a 15 HP motor and they said it was my problem to solve with an electrical contractor on my side (secondary). We did the open delta just for the motor. By the way the open delta provides only 60% of the power for the same KVA as a delta or Y connected transformer bank.
This is all recollection from my early years as an Air-conditioning technician in Phoenix.
Ron
Arc weld
Veteran Member
Canada is 60 HZ for sure but there are companies that bring oodles of used machine tools over from Europe to sell here.
stuckmotor
Super Member
- Joined
- Sep 23, 2009
- Messages
- 7,639
- Location
- Lower Up State S.C.
- Tractor
- AC WD 34 hp/3500 lbs MF 261 60 hp/5380 lbs
Thanks. Now, I know.
buickanddeere
Super Member
European 50Hz 380/416V equipment also operates just fine on 60hz 440/480.
How is it that your company is using equipment from Canada? Did some company close a Canadian branch and re-locate the equipment to the US to save operating costs?
Mark @ Everlast
Advertiser
Ron,
They are still installing delta systems all across the country these days. It's used on farms, factories and all manner of shops, and facilities. 208 can be in open delta or wye configuration. 208 isn't as common anymore, but 240 Delta is. 480 delta is as well. In my area of the country, due to emc cooperatives dominating power service, it's hard to find wye, though they will run it for you if you have the cash.
grsthegreat
Super Star Member
oh, they still use 208 wild leg systems. Im working in a shop thats only 4 years old and it has that installed.
All the panels are filled with most of the B legs empty cause there arnt many 3 phase pieces of equipment being used. Im going to install a transformer and add a 240 single phase panel next to all the 3 phase mess and do some rewiring.
All the panels are filled with most of the B legs empty cause there arnt many 3 phase pieces of equipment being used. Im going to install a transformer and add a 240 single phase panel next to all the 3 phase mess and do some rewiring.
buickanddeere
Super Member
Never seen an open Delta utility transformer or a wild leg Delta system in Ontario in 30+ years. Three phase is usually 120/208 Wye and 347/600Wye. Some 600V delta systems for heavy industry. Then a small 600delta to 347/600wye or 600delta to 120/208 wye is used for local single phase loads.
More and more installations with a single phase service then a VFD or transformer and VFD is used together to convert single to three phase.
More and more installations with a single phase service then a VFD or transformer and VFD is used together to convert single to three phase.
