What is power supply isolation?
Isolated power is a special type of power distribution system used in critical care areas of health care facilities. It is designed to protect patients and staff from electric shock hazards associated with ground-fault currents present during certain medical procedures. Isolated Power Systems (IPS) use a hospital grade isolation transformer to isolate both power conductors from the building’s electrical ground, eliminating the neutral-ground reference. Thus, the term “un-grounded” is often used to describe IPS. Unlike ordinary Ground Fault Circuit Interrupters (GFCI), Isolated Power Systems do not trip or shut down power to critical medical equipment when an initial ground-fault occurs.
What are the components of an Isolated Power Panel?
Below are the components of and isolated power panel and the function of each:
- Enclosure (or backbox) is constructed of galvanized steel. The enclosure is recessed or flush-mounted in the wall cavity during the rough-in stage of construction.
- Stainless Steel Front Trim Panel is installed on the backbox in the final stage of installation. The front trim includes access to the system’s Line Isolation Monitor and circuit breakers.
- Hospital Grade Isolation Transformer provides electrical isolation for patient care area and blocks the flow of hazardous line-to-ground faults.
- Panelboard Interior with up to 16 branch circuit breakers distributes the isolated power to energized equipment throughout the patient care area. A Primary Main breaker is also provided at the input side of the system. Its rating depends on the capacity of the isolation transformer (kVA) as well as the primary voltage.
- Line Isolation Monitor (LIM) continuously monitors the hazard current of the IPS. If the LIM detects a Total Hazard Current (THC) exceeding 5mA, a visual and audible alarm is initiated to alert medical personnel. The patient is still protected, and the alarm can be silenced while the case continues.
- Receptacles are contained in some isolated power panels to provide power connections in a limited space.
What is the purpose of a Line Isolation Monitor?
All Isolated Power Systems employ a special device known as a Line Isolation Monitor, or LIM. This device constantly measures the line-to-ground impedance of both isolated line conductors. Since hazard current is inversely proportional to ground impedance, the LIM calculates and displays the Total Hazard Current (THC) of the system. If the THC exceeds 5mA, an audible and visual alarm is initiated to warn that a first fault has occurred on the system. This signifies that an un-safe fault current could begin to flow through the system if a secondary fault occurred, providing a path for this current. Activation of the LIM alarm does NOT indicate that dangerous fault currents have occurred, only that one layer of protection has been compromised and the potential for this now exists.
What should I do when the line isolation monitor (LIM) goes into alarm?
- An alarm does not mean there is imminent danger. Do not endanger patient by discontinuing procedure prematurely.
- If possible, immediately notify personnel responsible for maintaining equipment.
- If it is clear that the alarm is directly related to a particular device, disconnect that device from the system. Depending on the nature of the device, this may not be possible. For example, life-support equipment.
- Once the procedure is completed and the patient has been safely removed from the area, authorized personnel should attempt to identify the root cause of the fault. Likely causes may include damaged wire or power cord insulation, liquid intrusion into energized equipment or wiring, or faulty equipment.
- If the cause is not readily identifiable, turn off all circuit breakers on the isolation power panel. Then turn on individual circuit breakers one at a time and observe the circuit’s relative hazard current contribution as displayed on the LIM. Identify which circuits contribute the largest amount of hazard current. This will narrow down the number of devices that may be associated with the alarm.
- Contact PG LifeLink Field Service for further troubleshooting at 877-445-4123 or click here to email a customer service rep.
What are your Isolation Power Panel or Line Isolation Monitor (LIMs) testing recommendations?
- Regular inspection and testing are vital to ensuring that Isolation Power Panels perform their patient protection and fault monitoring role.
- NFPA 99 Article 18.104.22.168.4 requires that all LIMs be tested and documented at least every 12 months (every 1 month for older analog designs). LIMs must also be tested after any “repair or renovation” to the system using external fault loads (22.214.171.124.5).
- PG LifeLink’s qualified Field Service Technicians are specifically trained on all brands and models of Isolated Power Panels. Call PG LifeLink to scheduled testing at 877-445-4123 or click here to email a customer service rep.
What type of Isolated Power Panel do I need?
PG LifeLink manufactures a wide variety of isolated power panels to fit your needs. Our Plus Series Isolated Power Panels offer smaller panel sizes and an industry leading six-inch backbox depth for increased space in the operating room. The following models are available:
- Model IPP-P: Multi-purpose isolated power panel that is typically used to supply 120V equipment loads in operating rooms
- Model IPX-P: Duplex isolated power panel containing two separate isolated power systems within one enclosure, simplifying installation and maximizing available space
- Model IPD-P: Dual voltage isolated power panel allows single incoming primary feed to drive two separate output voltages from a single transformer
- Model IPL-P: Designed to power laser outlet modules located in multiple procedure rooms from a single, centrally located panel
What is a backbox?
A backbox is a heavy-duty galvanized steel “cabinet” that has a hinged stainless-steel front door that contain all isolated power components.
Do you sell backboxes only?
Do you provide urgent emergency quotes and product?
Yes. Project quotations can be quoted sooner than our regular policy which is one day of request and drawing submittals are sent within two days of a purchase order. Call us for an emergency quote at 800-287-4123.
What methods of payment do you accept?
We accept payment by check, ACH, all major credit cards* (VISA, MasterCard, American Express, Discover) and wire payments. *Credit card surcharge may apply.
Can you work with my shipper?
Yes, we can work with your shipper of choice: freight, UPS, FedEx, etc. Call our shipping department for more information at 800-287-4123.
What are the LabLink color options?
LabLink’s standard finish is a clear satin anodized aluminum. As an option, we do offer a powder coat finish using a RAL color. Click on this link to view available RAL colors. For more information call a LabLink sale representative at 800-287-4123 or contact us via our website at https://www.pglifelink.com/lablink.