Flange-Mounted Safety Switch Assemblies - Grainger Industrial Supply

H provides overcurrent protection, has a low amperage interrupting rating (AIC), and does not have a degree of time delay. They are often referred to as a non-time delay fuse.
J have a high amperage interrupting rating (AIC) for protecting against short circuits and are ideal for IEC motor starter applications. They are current-limiting to prevent electrical damage by disconnecting circuits before they're exposed to the full magnitude and duration of an overcurrent.
K have amperage interrupting ratings (AIC) for higher interrupt applications and are current-limiting to prevent electrical damage by disconnecting circuits before they're exposed to the full magnitude and duration of an overcurrent. They're not labeled as current-limiting since they don't have a rejection feature. They are for general purpose use in existing installations that require a high-sensitivity, fast-blow fuse. These fuses are highly sensitive to changes in current flow and don't tolerate temporary overload currents or power surges, so they open within seconds of being exposed to overloads and short circuits. They have no indicator for identifying a blown fuse, so they're sometimes used with an indicating fuse block or cover.
R are current-limiting and have a short-circuit interrupting rating to prevent electrical damage by disconnecting circuits before they're exposed to the full magnitude and duration of an overcurrent. These fuses are the same size as Class H and K fuses, but have a rejection feature that prevents an accidental downgrade from a current-limiting system. Their modified terminals ensure a match with the rejection clips in Class R fuse holders that prevent the installation of fuses with a lower interrupting capacity. They're typically used in newer equipment, but can also be used with a Class H fuse holder to upgrade older installations from Class H or K fuses for improved overcurrent protection.

All Products

Line by Line

Sign In

Order Lookup

Fusible Disconnect Switch Assemblies

Non-Fusible Disconnect Switch Assemblies

Handles & Operating Mechanisms

Door Closing Mechanism

Handle Mechanism

Replacement Handle