Motor & Pump Protection
Motor & Pump Protection
(OP)
If there is a fault at the Drive end side bearing of the pump, the bearing & the shaft gets overheated & damaged.Should the induction motor does not trip before this condition.The motor thermal overload shall operate to prevent such condition.please clear my doubts
thanks in advance
thanks in advance





RE: Motor & Pump Protection
What size motor?
What type of pump?
What is the pump pumping?
How long does it take to heat up?
And the general motor housing does not seem to heat up too much?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Motor & Pump Protection
It cannot protect against bearing damage in a driven machine or in the motor for that matter.
Bearing damage can lead to shaft damage from scraping/wear/heating.
The motor shaft should not be damaged from any associated torque overload since worst-case torque overload is typically locked rotor and shaft can withstand that (and motor would trip on overload within a short period with no winding thermal damage expected).
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RE: Motor & Pump Protection
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RE: Motor & Pump Protection
These signals are transmitted to trending software in the control room.
Short answer:- No, motor overload protection will not protect pump bearings.
Bill
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"Why not the best?"
Jimmy Carter
RE: Motor & Pump Protection
The motor is 900 KW & not run with VFD, voltage level 4.16 KV, Rated current 156 A.
Is it normal for the motor to take 1MW load.
Zaza
RE: Motor & Pump Protection
A change in the dynamic head, a change in the temperature of the product, a change in the SG of the product and a lot of other things will make more difference to motor current than the increase in current caused by failing bearings.
It depends:
Does the motor have a service factor greater than 1?
Why do you think that the motor is taking over 1MW load?
How are you measuring the load?
For bearing protection look here:
http:/
Bill
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"Why not the best?"
Jimmy Carter
RE: Motor & Pump Protection
An OL relay will pick up a bad bearing only after the friction it causes increases the motor loading into that OL detection range, in other words, LONG after the damage is done. That is not what a basic OL relay is designed to do.
If I had to guess, I'd say you have an OL relay selected based on the lowest cost, not the best protection of your motor investment. You need something more sophisticated, what we refer to as a Motor Protection Relay, along with the proper sensors as mentioned above.
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RE: Motor & Pump Protection
Provide Bearing RTD's and Vibration sensors to protect your motor as well as your pumps mechanically.
RE: Motor & Pump Protection
You need to add bearing RTD's and a monitoring relay.