Baldor ODP series - Suggested bearing and winding RTD setting guidelines

Maintenance & Troubleshooting 3‐5MN400
Suggested bearing and winding RTD setting guidelines
Most large frame AC Baldor motors with a 1.15 service factor are designed to operate
below a Class B (80°C) temperature rise at rated load and are built with a Class H
winding insulation system. Based on this low temperature rise, RTD (Resistance
Temperature Detectors) settings for Class B rise should be used as a starting point.
Some motors with 1.0 service factor have Class F temperature rise.
The following tables show the suggested alarm and trip settings for RTDs. Proper
bearing and winding RTD alarm and trip settings should be selected based on these
tables unless otherwise specified for specific applications.
If the driven load is found to operate well below the initial temperature settings under
normal conditions, the alarm and trip settings may be reduced so that an abnormal
machine load will be identified.
The temperature limits are based on the installation of the winding RTDs imbedded in
the winding as specified by NEMA. Bearing RTDs should be installed so they are in
contact with the outer race on ball or roller bearings or in direct contact with the sleeve
bearing shell.
Winding RTDs - Temperature Limit In 5C (405C Maximum Ambient)
Motor Load
Class B Temp Rise 3 80°C
(Typical Design)
Class F Temp Rise 3 105°C Class H Temp Rise 3 125°C
Alarm Trip Alarm Trip Alarm Trip
3 Rated Load 130 140 155 165 175 185
Rated Load
to 1.15 S.F.
140 150 160 165 180 185
Note: S Winding RTDs are factory production installed, not from Mod-Express.
S When Class H temperatures are used, consider bearing temperatures and relubrication requirements.
Bearing RTDs - Temperature Limit In 5C (405C Maximum Ambient)
Bearing Type
Oil or Grease
Anti-Friction Sleeve
Alarm Trip Alarm Trip
Standard* 95 100 85 95
High Temperature** 110 115 105 110
Note: * Bearing temperature limits are for standard design motors operating at Class B temperature rise.
** High temperature lubricants include some special synthetic oils and greases.
Greases that may be substituted that are compatible with Polyrex EM (but considered as
“standard” lubricants) include the following:
- Texaco Polystar - Rykon Premium #2 - Chevron SRI #2
- Mobilith SHC-100 - Pennzoil Pennzlube EM-2 - Chevron Black Pearl
- Darmex 707 - Darmex 711 - Petro-Canada Peerless LLG
See the motor nameplate for replacement grease or oil recommendation.
Contact Baldor application engineering for special lubricants or further clarifications.