Here are the important things about Coil-Lock

What is a Voltage Drop?

The wires that carry current have an innate resistance, or impedance, to the flow of current. How much voltage is lost due to that impedance is known as Voltage Drop.

If the voltage drop is severe it can create issues with whatever device is receiving power, in turn, this causes the device to work harder and consume more power than should be necessary.

Voltage Drops can occur from variables outside of a company’s control like Utility System Faults, Motors Starting, Load Variation, and Weather Conditions.

Momentary voltage drops are responsible for billions of dollars per year in lost revenues to manufacturing and process industries.

We Solve the Problem of Momentary Voltage Drops and Dips.

Power Quality Solutions, Inc. (PQSI) is a cost effective solution for power quality problems. The Coil-Lock hold-in-devices keep motors and other critical process control elements engaged during momentary voltage drops and dips.

PQSI’s Coil-Lock allows critical power processes and elements to stay active during power disturbances. This keeps relays, contactors, and motor starters engaged.

Coil-Lock reduces and minimizes the likelihood of these uncontrolled variables to interrupt business machines and processes equipment.

Coil-Lock is available in multiple models and compatible with most all solenoid operated relays and contactors.

It’s so easy! Installs within minutes and saves money! Downtime is decreased, Production is increased.

Typical Voltage Sag Events* in Real-Time Terms


*Electric Power Research Institute (EPRI), Canadian Electric Associations (CEA), and National Power Laboratory (NPL).

PQSI Coil-Lock Coil-Hold-In-Device Provides SEMI F47 Voltage Sag Immunity


PQSI Coil-Lock Coil-hold-in-Device Protects for 75% Deep Sags (i.e. 25% Remaining Voltage)