advertisement
from the Humorous department...
Using duplex type RTDs in High Voltage Motor protection
Engineering and workplace issues. topic
Posted by Kunal S Dabi on 24 October, 2009 - 8:16 am
1. What is the advantage of using duplex type RTDs in High Voltage Motor protection (Motor stator and winding)?

2. Is it possible to replace Simplex type RTD with Duplex type RTD on site? If yes then which type of implication require in Motor & receiving end of RTDs signals like Motor protection relay, PLC, DCS etc.


Posted by Carl on 25 October, 2009 - 3:10 pm
Without knowing the application of High Voltage motor protection, let me state some basics of RTDs:

An RTD is a resistor, so it requires an excitation source current to develop a voltage drop that the instrumentation can 'see' or 'read'.

An RTD's 'signal' cannot be paralleled when more than one temperature reading is needed by multiple instruments.

One means of getting multiple readings is to use multiple RTD's in one sheath: dual elements or duplex sensor assemblies. One RTD connects to one instrument, the other RTD connects to the other device.

It is entirely possible to replace a Simplex (single RTD element) with a Duplex (dual RTD elements) as long as the probe physically fits in the same location.

The only implications I can think of involves connecting the 2nd RTD to some instrument which will needs to be RTD input compatible (you can't connect an RTD to a thermocouple or 0-5Vdc analog input) and the RTD element type must match the analog input type: 100 ohm Pt or 120 ohm nickel or whatever.


1 out of 1 members thought this post was helpful...
Posted by Phil Corso on 25 October, 2009 - 8:28 pm
Kunal... typically, RTD's used to monitor motor temperature are embedded in the winding slot. Thus, they are not replaceable and a duplex arrangement increases monitoring reliability!


Regards, Phil Corso


Your use of this site is subject to the terms and conditions set forth under Legal Notices and the Privacy Policy. Please read those terms and conditions carefully. Subject to the rights expressly reserved to others under Legal Notices, the content of this site and the compilation thereof is © 1999-2014 Nerds in Control, LLC. All rights reserved.

Users of this site are benefiting from open source technologies, including PHP, MySQL and Apache. Be happy.


Fortune
Q: How many Martians does it take to screw in a lightbulb?
A: One and a half.
Advertise here
advertisements
Servo, stepping motor control, analog & web HMI in one system!
164-page eBook free download - EtherCAT Applications Guide
Servo, steppers, analog, digital & web HMI - Fully Integrated!
Time to incorporate data handling, web HMI and motion in one system!
View free setup and multi-vendor EtherCAT demo videos online
our advertisers
Help keep our servers running...
Patronize our advertisers!
Visit our Post Archive