Long-Time Rating Plug

One of four interchangeable long-time rating plugs can be used to limit the long-time pickup setting range for higher accuracy of the long-time overcurrent protection.

Selecting the Long-Time Rating Plug

The setting range for the long-time current setting on MicroLogic trip units is defined by the long-time rating plug.

The available rating plugs are listed in the following table:

Part number	Setting range for the Ir value
C33542	Standard	0.4–1 x Ir
C33543	Low setting	0.4–0.8 x Ir
C33544	High setting	0.8–1 x Ir
C33545	Without long-time protection, Ir = In for short-time protection setting

NOTE: If no long-time rating plug is installed, the trip unit continues to operate under the following downgraded conditions:

The long-time current setting Ir is 0.4.
The long-time time delay tr corresponds to the value indicated by the adjustment dial.

Replacement Procedure

DANGER
HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, CSA Z462, NOM 029-STPS or local equivalent. This equipment must only be installed and serviced by qualified electrical personnel. Turn off all power supplying this equipment before working on or inside this equipment. Always use a properly rated voltage sensing device to confirm power is off. Put back all devices, doors, and covers before turning on power to this equipment. Beware of potential hazards, and carefully inspect the work area for tools and objects that may have been left inside the equipment. Failure to follow these instructions will result in death or serious injury.

DANGER

HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH

Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, CSA Z462, NOM 029-STPS or local equivalent.
This equipment must only be installed and serviced by qualified electrical personnel.
Turn off all power supplying this equipment before working on or inside this equipment.
Always use a properly rated voltage sensing device to confirm power is off.
Put back all devices, doors, and covers before turning on power to this equipment.
Beware of potential hazards, and carefully inspect the work area for tools and objects that may have been left inside the equipment.

Failure to follow these instructions will result in death or serious injury.

NOTICE
Hazard of trip unit deterioration Prior to running dielectric strength tests, it is mandatory to disconnect all electrical auxiliaries (for example, MX or MN voltage releases) connected to the device. Failure to follow these instructions can result in equipment damage.

Follow this procedure to change or remove the rating plug.

Open the circuit breaker.
Open the protective cover of the trip unit.
Record switch settings.
Unscrew the long-time rating plug mounting screw.
Remove the adjustable rating plug.
Inspect mounting area for debris and contamination.
Take out the replacement rating plug.
Gently push in the replacement rating plug.
Tighten the long-time rating plug mounting screw.
Set trip unit settings to values recorded previously or modify settings.