PTC wiring in encoder cable

Plc_User

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• Oct 31, 2009

• #1

We want to use spare wires in the encoder cable to wire also the ptc of the motor. Only thing I am worried about is the voltage drop on the wires. The standard cable we use have wires of 0.35 mm2 or 22AWG and the cables have a maximum length of 50m or 160 feet. Will this cause trouble?
Thanks

 

leitmotif

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• Oct 31, 2009

• #2

Plc_User said:

We want to use spare wires in the encoder cable to wire also the ptc of the motor. Only thing I am worried about is the voltage drop on the wires. The standard cable we use have wires of 0.35 mm2 or 22AWG and the cables have a maximum length of 50m or 160 feet. Will this cause trouble? Thanks

Click to expand...

Uhhhh what is ptc in a motor?
Dan Bentler

 

Mickey

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• Oct 31, 2009

• #3

leitmotif said:

Uhhhh what is ptc in a motor?
Dan Bentler

Click to expand...

http://www.google.com/search?q=ptc+...s=org.mozilla:en-US:official&client=firefox-a


To the OP. It probably will not be a problem sense a thermistor draws very little current. You may have to consider the wire resistance. What are you connecting the thermistor to?

 

Last edited: Oct 31, 2009

ArikBY

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• Nov 1, 2009

• #4

I would consider the noise which can affect on the encoder signal.
The PTC come from the motor JB.
I would not do so.

 

leitmotif

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• Nov 1, 2009

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Thanks Mickey
Ran out of brain power to remember all acronyms this week.

Dan Bentler

 

Gil47

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• Nov 1, 2009

• #6

A PTC is a motor thermistor and if you see how they are placed in a motor winding you would think twice before you ran the wire from a PTC thermistor in with most other wiring.

If wires chafe, or motor burns out, there is a remote possibility of a supply voltage being introduced into that cable, which would have no real effect on the thermistor, but could affect other items such as your case encoders.

 

Plc_User

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• Nov 1, 2009

• #7

Has anyone seen this configuration (ptc in encoder cable) in practice?

 

BryanG

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• Nov 1, 2009

• #8

I am with Gil47 on this one. The risk of getting mains voltage on the low voltage circuit far outweighs the benefit. Run the extra cable!!!!

Bryan