DC Starter Coil
- Thread starter sii
- Start date
- Status
stew
Senior Member
- Location
- federal way,washington
nope. connect one side of the dc to the nc contact of the pushbutton. connect the other side of the dc source to a2. connect the no contact to a1.
Last edited:
stew
Senior Member
- Location
- federal way,washington
glad i could open ypur eyes. Joe
DC Holding
DC Holding
That used to be common in swichgear (ITE Imperial is one ICan remember).
Considerable DC current is required to "pick up" the contactor. Once you have the contactor closed you don't want all that current going through the coil, it will be noisy, get hot and may permanently magnatize the steel in contactor (meaning it may not open when you push the off or stop button). Some contrators use seperate coils some use tapped.
Contactors or starters with a mechanical latching system don't have that problem.:roll:
DC Holding
That used to be common in swichgear (ITE Imperial is one ICan remember).
Considerable DC current is required to "pick up" the contactor. Once you have the contactor closed you don't want all that current going through the coil, it will be noisy, get hot and may permanently magnatize the steel in contactor (meaning it may not open when you push the off or stop button). Some contrators use seperate coils some use tapped.
Contactors or starters with a mechanical latching system don't have that problem.:roll:
Last edited:
kwired
Electron manager
- Location
- NE Nebraska
The NCI contact opens after pickup is accomplished. This places the two coils in series in the left image and completely isolates the pickup coil on the right image. All of this is likely done for you they are just showing you what is there.
Otherwise wire like any other coil, full voltage must be applied to A1 and A2 on the left image and A1 and A2 top on the right image. NO 2 to 3 contact is used for holding coil if a 3 wire start stop control is used, just like other contactors.
Otherwise wire like any other coil, full voltage must be applied to A1 and A2 on the left image and A1 and A2 top on the right image. NO 2 to 3 contact is used for holding coil if a 3 wire start stop control is used, just like other contactors.
Others have pretty much covered it. It takes more current to close the contactor than to hold it in. I've seen this arrangement where the NC contact is sometimes referred to as an economy circuit.
With an AC contactor it happens naturally. There is high current when the pole faces are apart and there is a gap (contactor open) and the current drops when the pole faces close removing the gap in the magnetic circuit.
- Status