Pump Protection against Dry Run with eMPR300D, eMPR300I & iMMR Relays

Problem:

Dry running pumps experience rapid temperature rise, damage to seals, bearings, and impeller, leading to permanent damage to pumps.

Traditional Solution:

Float switches or pressure sensors—often unreliable, difficult to maintain, and likely to fail frequently.

Solution:

With the help of eMPR & iMMR, Undercurrent protection function is able to detect the sudden, measurable drop in motor current or power consumption that occurs when the pump loses its water load (dry run).

Dry Run Condition and its effects:

Occurs when a pump runs without fluid (no load torque or back pressure).

The motor is under loaded, so current drops significantly below rated value.

Can cause over heating due to lack of cooling fluid, even though current is low.

Use of eMPR & iMMR for this problem:

High reliability since the relay constantly monitors the load current, regardless of liquid level or pressure switch state.

Detects a drop in load current or power using non-intrusive electrical measurements, then automatically trips the motor to prevent overheating and mechanical damage ensuring safety, reliability, and long equipment life.

• In eMPR300D & eMPR300I we have settable pickup value range from 20% to 90% of Im and settable delay of 1 to 300 secs. In iMMR we have settable pickup value range of 15% to 100% of Im and settable delay of 0.100 to 600 secs.
• By using eMPR & iMMR our motor is protected during Dry Run Condition.

For further details, please contact: cic@LK-EA.com