Rockwell Automation 2100 CENTERLINE Low Voltage Motor Control Centers - Manual (Page 97)

Rockwell Automation Publication 2100-IN012E-EN-P - February 2012 97
Maintenance Chapter 9
Use Thermal Infrared or
Other Temperature
Measurement Techniques
for Preventive Maintenance
Use the following procedure when using thermal infrared or other temperature
measurement techniques as part of a periodic preventative maintenance program
on CENTERLINE 2100 Low Voltage MCCs.
1. Use test equipment to determine the temperature differential and the
temperature rise of accessible components within the unit.
2. Determine the services and repair recommendations based on the
temperature category in the following guidance chart.
Inspect the Units for Signs of Overheating
1. If there are no signs of overheating and thermal infrared tests indicate
service is not necessary, document the units as acceptable.
Use this information for reviewing the mean time to maintenance for
preventative maintenance for the specific facility.
ATTENTION:
Temperature measuring techniques are often performed with the units fully
energized and the doors and covers open.
Use extreme caution when performing these measurements so that
energized parts are not shorted.
If care is not taken, electrical shock, severe injury or death will result.
When working on or near energized electrical equipment, follow established
electrical safety-related work practices. Refer to NFPA 70E Standard for
Electrical Safety in the Workplace.
Table 13 - Temperature Guidance
Category Temperature
Differential
(1)
Temperature
Rise
(2)
Repair/Service
°C °F °C °F Service Interval Recommended Action
1 < 10° < 18° < 70° < 126° No service or repair required. See step 1 below.
2 10°...25° 18°...45° 70°...100° 126°...180° Service or repair the unit at next maintenance schedule (not
greater than six months but continue monitoring as a part of
preventive maintenance.) See step 2 below.
3 25°...50° 45°...90° 100°...115° 180°...207° Service or repair the unit within the next two weeks and
monitor the unit at the next maintenance interval.
4 > 50° > 90° > 115° > 207° Shutdown the unit and repair. Verify that the temperature is
reduced after re-energization.
(1) Temperature (measured or rise) differential between adjacent phases or like elements. Load between phases must be balanced with a normal variation not exceeding
seven percent.
(2) Measured temperature less ambient.
Due to difficulty obtaining accurate infrared temperature measurements from highly reflective surfaces, we recommend using temperature differential readings in
determining the Service/Repair guidelines, for example, emissivity of tin or silver plated material.