Temp97
Bronze Member
What does N. O. Terminal and N.C. Terminal mean? This is listed on a PTO sitch for a deck mower. I'm thinking one's + and one's -..
electrical terminals?
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biggerten
Gold Member
Normally Open
Normally Closed
There's probably a third terminal labeled Common, as well. Or perhaps Ground is common, and there is no third terminal.
In the unactivated (normal) state, the Common (in this case, maybe Ground) is connected to the above.
For example, let's connect a wire to the N.O. terminal, and assume the common is ground. With the switch not activated, the circuit is open. When the switch is activated, the N.O terminal would be grounded.
Normally Closed
There's probably a third terminal labeled Common, as well. Or perhaps Ground is common, and there is no third terminal.
In the unactivated (normal) state, the Common (in this case, maybe Ground) is connected to the above.
For example, let's connect a wire to the N.O. terminal, and assume the common is ground. With the switch not activated, the circuit is open. When the switch is activated, the N.O terminal would be grounded.
weedpharma
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Unless you have a good supply of spare fuses, DO NOT connect + & - from your battery to the switch!
Weedpharma
BobRip
Elite Member
Unless you have a good supply of spare fuses, DO NOT connect + & - from your battery to the switch!
Weedpharma
Might need some spare switches to. That can be some major current before the fuse blows or the wire melts.
J_J
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I believe the wire from the electric clutch would go to the n. o. terminal. 12v going to the common terminal. No continuity through the switch. So when switch is on, you apply 12v to the clutch. The n.c. is used when you want to open/break a circuit.
I've attached a link that shows the switch for my mower deck PTO. The switch has several terminals but I only have juice in the one terminal when I put the tester on it (I believe it's the N.C. one).. I have no idea what the rest of these terminals do. With all the safety features on this thing I'm thinking that's what they are used for (grounding??).
Amazon.com: 725-1716, 725-1752, 725-3233, MTD PTO Switch. Ariens 5221, 1545600: Home Improvement
Amazon.com: 725-1716, 725-1752, 725-3233, MTD PTO Switch. Ariens 5221, 1545600: Home Improvement
J_J
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- JACKSONVILLE, FL
- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
A normally closed switch, N.C. would be something like an oil sender, At start up, no oil pressure, then the switch has continuity until engine is started and oil pressure builds up and then it opens, and the light goes out. Normally closes switch would also apply to a phone jack. The switch is closed until you plug a phone plug which opens the switch.
A normally closed switch is closed when the switch is connected. You would not want it to be connected when you turn the master power on. The power for the deck clutch is coming from the battery, probably through a fuse, and should go to a terminal that will supply voltage to another terminal when activated. Without the engine running, and you apply power, all you will hear is a click as the electric clutch is engaged. However if you wire it up wrong, as soon as the engine is running, the deck clutch has voltage, and the blades are spinning. Just wire it up using some good logic. If you have a factory switch, just replace it.
Most switches are used in the N.O. mode for obvious reasons. Drills, motors, etc.
A normally closed switch is closed when the switch is connected. You would not want it to be connected when you turn the master power on. The power for the deck clutch is coming from the battery, probably through a fuse, and should go to a terminal that will supply voltage to another terminal when activated. Without the engine running, and you apply power, all you will hear is a click as the electric clutch is engaged. However if you wire it up wrong, as soon as the engine is running, the deck clutch has voltage, and the blades are spinning. Just wire it up using some good logic. If you have a factory switch, just replace it.
Most switches are used in the N.O. mode for obvious reasons. Drills, motors, etc.
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