Popular tips

What is a LIM panel?

What is a LIM panel?

The Line Isolation Monitor (LIM) continuously monitors the Total Hazard Current (THC) of an Isolated Power System in the Healthcare industry. LIMs are the piece of the Isolated Power Panel which monitors the hazard current and alarms if the electrical current has reached a dangerous level.

What is line isolation monitor testing?

Testing Isolation in Emergency Rooms is Mandatory Health Care Facilities insist on Line Isolation Monitor Testing (LIM) to ensure the safety of their patients. Line Isolation monitors are continually operating, and indicate possible leakage or fault currents from isolated conductor to ground.

What is line isolation?

Line isolation systems (isolation transformer + line isolation monitor) protect persons from electrocution by turning a normal “grounded system” (that exists outside the operating room) which only needs a single fault to cause electrocution into a “protected” system in which two faults are needed to deliver a shock.

Is power grounded in the operating room?

In an isolated system, neither of the 120 volts AC power wires available at the power outlets are connected to earth ground. They are both “floating”. A grounded power system for the wall outlets in an operating room is just like what you probably have in your home’s living room or TV room.

How is a Lim circuit tested in NFPA?

– NFPA 99 – 2012 “6.3.3.3.2 Line Isolation Monitor Tests. The line isolation monitor (LIM) circuit shall be tested after installation, and prior to being placed in service, by successively grounding each line of the energized distribution system through a resistor whose value is 200 x V (ohms, where V equals measured line voltage.)

How is line isolation monitor ( Lim ) circuit tested?

The line isolation monitor (LIM) circuit shall be tested after installation, and prior to being placed in service, by successively grounding each line of the energized distribution system through a resistor whose value is 200 x V (ohms, where V equals measured line voltage.) The visual and audible alarms (see 6.3.2.6.3.2) shall be activated.”

When does a Lim need to be tested?

The LIM is a test instrument per 3.3.97 definitions, so needs to be tested to see if it is in the specifications of the manufacturer and NFPA requirements. When the LIM is defective or out of the panel the room must be shut down. Do you have a spare LIM in your stock?

How often should a Lim be isolation tested?

For example, LIMs that have an analog meter the testing is monthly. If the LIM does not have self-test features, then testing is monthly. For LIMs with digital meters and self-testing features testing is annually. Isolation Power Specialist works with your facility to provide testing and certification.