NEMA Hospital Grade Reference Chart

Hospital Grade (HG) Standards

Plugs, Connectors, Receptacles and Power Cords used in medical applications must have a green dot prominently displayed on the housing surface to indicate conformance with Underwriter Laboratories specifications UL817, UL60601-1 and UL498. Further, UL60601-1 states that all patient care equipment must use power cords with hospital grade attachment plugs.

Hospital Grade wiring devices and cords must meet vigorous material, construction, and testing standards.

1. Prong blades must be of solid brass construction without folding.
2. A retaining strain relief type device must be added to the inside of the plug mold to prevent any potential stress to connections and ensure grounding reliability.
3. Must pass the following stringent UL tests:

Plug and Connector Testing

HG Test: Impact Test - A plug or connector wired with the minimum size flexible cord is subjected to an impact from a 10 pound cylindrical weight having a flat face with a 2 inch diameter dropped from a height of 18 inches. After the test, there shall be no breakage or other damage that may affect the function of the device.

HG Test: Mechanical Drop Test - The cord connector is wired to #18 AWG flexible cord and suspended horizontally. It is released so it impacts a hardwood surface 45 inches below the point of suspension. This is repeated for 1,300 cycles. After the test, there shall be no breakage, deformation or other effect that may interfere with the function of the device.

HG Test: 500 Pound Crush Test - A wired plug or connector is placed between two hardwood slabs while subjected to a force which is progressively increased to 500 pounds. After the test, there shall be no breakage, deformation or other effect that may interfere with the function of the device.

HG Test: Strain Relief Test - While assembled to a plug or connector but not wired to the terminals; the cord must remain securely fastened after a straight pull of 30 pounds and a rotary motion within 3 inch circles with a 10 pound force applied for two consecutive hours. Displacement of conductors, insulation and outer jacket of the flexible cord shall not exceed 0.031 inch. There shall be no cuts, rips or tears in the insulation of the cord.

Receptacle Testing

HG Test: Abrupt Removal of Plug Test - A steel bodied test plug with blades made of brass is inserted into the receptacle. A 10 pound weight dropped from at least 24 inches, pulls the plug out of the receptacle abruptly. This test is done eight times with the receptacle rotated in different positions to create the greatest stress to the face and contacts. Then, with the receptacle facing down, the grounding contact must retain a 4 ounce grounding pin with a 0.184 inch diameter for one minute. After this test there shall be no breakage of the receptacle that interferes with the receptacle function or to the integrity of the enclosure.