HOW TO READ A RATING (NAME) PLATE ON ELECTRIC MOTORS.

All electric motors and pumps have a rating plate.  Rating plates, also known as nameplates, identify essential data such as serial or model numbers, date of manufacture, load data, voltage, operating instructions and more that is specific to the electric motor. The level of information does vary slightly depending on the electric motor or pump brand as does the layout. 

All key information is detailed and at your fingertips when you need to install and run or replace the electric motor. Rating plates also detail base electrical data and are a good reference for electrical fault finding.  Below is an example name plate explaining each part.

The motor’s main rating plate shows the motor’s performance values with various connections at nominal speed. The rating plate also shows the efficiency level, year of manufacture and the lowest nominal efficiency at 100, 75, and 50 % nominal load.

If you need to replace your electric motor, the key information we need is:

• Frame size
• Speed (rpm) or pole (2, 4, 6 or 8)
• kW
• Phase (~): single or three
• Mounting configuration: feet (B3), foot and flange (B35) or B34 (foot and face), B14 face (no flange)

An easy way to capture this information is to take a photo of the whole motor to show how it is used, rating plate and how it is mounted then come in to see us at 471 Tremaine Avenue, Palmerston North.  Or email the photos to This email address is being protected from spambots. You need JavaScript enabled to view it..  We have vast stock of electric motors and will be able to help you with a replacement motor.

REMOVABLE FEET AND MULTIPLE BOLTS HOLES OFFERS VERSATILITY

Brook Crompton’s high efficiency three phase electric motors feature removable feet and multiple bolt hole locations around the motor, designed for flexibility and ease of installation in a variety of applications. These multi mounting offerings are available on both cast iron and aluminium electric motors.

• Mounting options for both aluminium and cast iron motors include B3 with feet and end shield, B5 large flange mounting, B35 with feet and large flange mounting, B14 small flange mounting and B34 with feet and small flange mounting.
• Removable feet enable the motor to be flange mounted horizontally or vertically.
• Removeable feet also helps when switching between different mounting options or when different configurations are required. The motor can then be easily adapted to space constraints or specific application needs.

• Multiple bolt hole locations allow the terminal box to be positioned to the left, right or top ensuring compatibility with a wide range of machine set ups.
• Multiple bolt holes also allow the motor to be adaptable to various mounting frames, including base plates or custom fixtures, ensuring suitability for different applications such as pumps, fans, and conveyors.

Whether mounted on a wall, at a specific angle, or in a confined space, the combination of removable feet and multiple bolt hole locations makes Brook Crompton motors highly versatile, user-friendly and suitable for a broad range of industries, including manufacturing, processing, and material handling. This flexibility reduces the need for bespoke solutions, simplifying installation for both new builds and retrofits.

Brook Crompton’s three phase electric motors range includes 2, 4, 6 and 8 pole with frame sizes from 63 through to 355 or 0.18 to 374 kW. Most sizes are available off the shelf for both aluminium and cast iron. Contact our sales team on 06 354 3651 or This email address is being protected from spambots. You need JavaScript enabled to view it. for further information or to discuss your requirements.

B3 foot mount and end shield with the termical box positioned either top, left or right.

B35 feet and large flange with terminal box positioned either top, left, or right. Remove feet for B5 mounting.

B34 feet and small flange mount with terminal box positioned either top, left or right. Remove feet for B14 mounting.

For information on mounting configurations and flange types click here.  For a quick refernce guide of this information click here.

The importance of bearing lubrication in electric motors.

Maintaining lubrication in electric motors is important as it:

• Reduces bearing friction.
• Helps prevent undue temperature rises and dissipate some of the heat generated.
• Helps prevent corrosion.

While most lubrication applications are ambient temperature based there are also extremities.  For instance, lubrication choice differs for electric motors at the top of Mount Ruapehu to a high heat application or the food industry.  As well as being application-based, lubrication also depends on:

• operating temperature
• motor shaft speed
• bearing size
• bearing load
• hours of operation
• environmental conditions/ contaminants
• vibration levels

It is also important the correct lubrication and/or mix of lubricants are used for application and relubrication.  Mixing incompatible lubrications will result in rapid bearing failure. The only sure way to prevent incompatibility issues is use the same lubrication, unless BOTH lubricant manufacturers state BOTH lubricants are compatible.  If in doubt, purge it out!

Lubrication levels for ball and roller bearings differ for horizontal and vertical shaft applications.

• Horizontal shaft applications the oil level should be maintained at approximate centre of lowest rolling element when motor is not operating.
• Vertical shaft applications the oil level should be maintained at approximately 50% submergence of rolling elements.

Relubrication frequency depends on the operating conditions, type and quantity of lubrication.  As a guide operating temperatures 50°C or less replace lubrication once a year.  For temperatures 80°C to 100°C replace at least quarterly.  For critical equipment, test lubrication at least quarterly to determine when lubrication replacement is required. Over and under lubricating can cause bearing failures.  Always use calibrated grease guns! 

Procedure for ball and roller bearings lubrication

1. Relubricate with shaft stationary & warm motor (near operating temperature).
2. Locate lubrication inlet and clean around it. Replace pipe plugs at inlets with lubricant fittings.
3. Remove relief plug and clean off any caked lubricant.
4. Add recommended volume of recommended lubricant.
5. Use a calibrated hand operated grease gun.
6. Run motor for 1/2 hour with relief plug removed.
7. Replace pipe plugs and wipe off excess lubricant.

If the motor manufacturer instructions/data sheet are not available, determine the appropriate lubricant through sample testing and lubrication intervals under the motors normal operating conditions. 

Please note sealed bearings do not require relubrication.

References

EASA BearingLubricationFreqQty_0119

EASA Electric Motor Bearing Lubrication_webinar_220406