Wye-Start Delta-Run Motor
- Thread starter jjason
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kspifldorf
Senior Member
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- My Old Kentucky Home
I googled " wye start delta run diagram " and got some great bites.
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Are you trying to build a better mousetrap? You can purchase this type motor starter - your control panel ? should only have something like lights for power available, start/stop, run indication,..... whatever else you need. Does that motor have 12 leads in the termination box?
Not sure what kind of license is LLE, but you could be looking trouble in the eye with your little project.
Where is the O.L. in the 2M Legs:-?
430.32 Continuous-Duty Motors.
...Where a separate motor overload device is connected so that it does not carry the total current designated on the motor nameplate, such as for wye-delta starting, the proper percentage of nameplate current applying to the selection or setting of the overload device shall be clearly designated on the equipment, or the manufacturer?s selection table shall take this into account.
430.32 Continuous-Duty Motors.
...Where a separate motor overload device is connected so that it does not carry the total current designated on the motor nameplate, such as for wye-delta starting, the proper percentage of nameplate current applying to the selection or setting of the overload device shall be clearly designated on the equipment, or the manufacturer?s selection table shall take this into account.
frenchelectrican
Senior Member
- Location
- Nord'est Wisconsin et Paris France
For typical Y-D starter as one person gave ya the photo and it fairly common to do that not using the OL at all otherwise you will need compley diffrent heater size to use that and also during Wye format the starting peroid is max of 15 to 30 seconds and also the starting current is controlled by timer so for so many of X seconds it should have open translation from wye to delta then from there delta conneciton will take care the rest.
Yes you can add a O/L heaters on that part but make sure you get fast acting heater during starting cycle.
Merci,Marc
- Location
- Wisconsin
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- PE (Retired) - Power Systems
You answered it yourself.
weressl
Esteemed Member
IMM_Doctor
Senior Member
Soft Start with Smart Motor Controller
Soft Start with Smart Motor Controller
I agree. We just installed a 125hp 480vac 3ph motor for a Hydraulic Power unit. We are quite satisified with the "start-up". (PUN intended).
Old school is Wye Start/Delta Run. The external timers get monkeyed with, you need three contactors, and there is still big voltage disturbances on the supply system when the "S" contactor shuts off, and the 2nd contactor comes on. (These start-ups are like slamming gears without using the clutch).
Our SMC installation is a smooth, progressive start-up to full RPM. (Like one smooth gas-pedal).
http://www.ab.com/industrialcontrols/products/solid-state_motor_control/soft_starters/smc-flex.html
Soft Start with Smart Motor Controller
Why bother, enter the 20th century and use SSRV.
I agree. We just installed a 125hp 480vac 3ph motor for a Hydraulic Power unit. We are quite satisified with the "start-up". (PUN intended).
Old school is Wye Start/Delta Run. The external timers get monkeyed with, you need three contactors, and there is still big voltage disturbances on the supply system when the "S" contactor shuts off, and the 2nd contactor comes on. (These start-ups are like slamming gears without using the clutch).
Our SMC installation is a smooth, progressive start-up to full RPM. (Like one smooth gas-pedal).
http://www.ab.com/industrialcontrols/products/solid-state_motor_control/soft_starters/smc-flex.html
- Location
- San Francisco Bay Area, CA, USA
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- Electrical Engineer
The only reason why some people still use Y-Delta is because they perceive them to be cheaper. 3 contactors and an OLR are still less expensive than an RVSS and a bypass contactor.Why bother, enter the 20th century and use SSRV.
But those people rarely consider the long term cost of ownership. Open transition Y-Delta starting is often very damaging to mechanical components and does indeed cause significant disturbance to the electrical system in the form of spikes, dips and surges. I personally hate them. In the years I was commissioning large soft starters and VFDs, whenever someone complained to me that they lost a lot of SCRs or Diodes and it couldn't be attributed to lightning, it always turned out they had a big old Y-Delta starter still in use somewhere in the plant. On the ones where I convinced them to replace it with another RVSS starter, the problems went away. For those that insisted I was nuts and said they "never had problems before", their issues continued. Yet they remained in denial about it.
weressl
Esteemed Member
Except they would be wrong. SSRV starters are either equal or less than a DYRVS. It also takes up more space in both the MCC or if it is standalone. Physical space can be estimated and is vairable, but the cost of the extra MCC section is hard cost. The extra cable for the additional three leads should also be added to the cost as well as the extra installation cost. Most SSRV's no longer employ full time SCR's, but have built-in bypass contacts. The SSRV offers superior overload protection, diagniostic capability and fine adjustment that can lower the inrush current compared to the D/Y starter for optimum performance and prolonging the life of the drive train by reducinig both electrical and mechanical wear.
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