Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations SSS148 on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Electrical control cables for PTC sensor wires 2

Status
Not open for further replies.

NickParker

Electrical
Sep 1, 2017
444
Is it okay to use Electrical control cables for PTC sensor wirs (from Field to MCC) which is to be laid along with Low voltage power cables.

PTC_wire_yxzcgo.png
 
Replies continue below

Recommended for you

Dear Mr. NickParker (Electrical)(OP)8 Sep 22 13:57
"...Is it okay to use Electrical control cables for PTC sensor wirs (from Field to MCC) which is to be laid along with Low voltage power cables. ? "
1. I noticed that two days had passed but there was no response.
2. I tried to answer it, for your consideration:
A PTC sensor operation/characteristic is based on the resistance.. When "cool", the resistance maintained at low ohmic value but sudden huge increase in ohmic value at certain "hot" temperature, (e.g. cool within say <100 Ohm to few kOhm when hot).
3. Its characteristic is independent of the Voltage, (4-20mA) current or induction of hi-frequency.
4. The sensor wire need on screening. However, as it is to be laid along with LV power cables, it shall have the same insulation voltage rating as the power cables.
Che Kuan Yau (Singapore)
 
I think you can use normal control cables for wiring PTC probes from field to the Temperature control relay type RM35.
The relay is to operate (signalling fault) only when the measured resistance is in excess of 3100 Ohms. So I guess running the control cable in parallel with the control cable for a few meters is not going to influence the relay operation.
If LV power cables are armoured with armour earthed at both ends, it helps avoid induction.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor