ABB 300-line overload relays Broad selection for positive motor protection

300-line overload relays

Broad selection for positive motor protection

The 300-line three-leg block overload relay includes features that provide positive motor

protection and added operator safety.

Dual bimetallic overload: The dual bimetallic overload relay anticipates motor overload,

responding to rising current and temperature with faster tripping on severe overloads for

better motor protection.

Isolated NO contact: Where it’s essential to monitor performance or diagnose faults, a 300-line starter

may be ordered with an additional isolated,  high fidelity, normally open contact in the overload relay.

This contact may be used for direct input to a programmable controller or interface with a computer.

Manual weld check: The overload relay can be manually tripped as a convenient way to check

against contact welding. Depressing the manual weld check arm trips the relay. A welded contact

can then be detected with a simple continuity check across the relay contact terminals.

Visual trip indicator: Unsafe overriding the reset arm is eliminated because overload reset occurs only

when the reset is released. A bright yellow visual trip indicator tells you at a glance if the relay has

tripped. An optional automatic reset overload relay is available for special applications upon request.

Interchangeable heaters: Overload relay heaters are completely interchangeable with 200-line starter

heaters, eliminating the need to stock an additional line of heaters.

The 300-line three-leg block overload relay includes features that provide positive motor

protection and added operator safety.

±10% adjustment: Relay trip points are factory calibrated for high accuracy. For added flexibility,

the trip current of the relay is adjustable ±10% to allow tuning the protection to any given motor

current and to eliminate nuisance tripping. A single calibration adjusts all three legs. The overload

relay is available in standard or ambient- compensated forms.

The CR324X solid-state overload relay provides added motor protection in critical

production processes where uptime is vital. It mounts directly to 300-line starters, and a

panel-mount version is also available for added application flexibility. Its advanced features can

save you time and money:

• Heaters are eliminated

• Phase loss protection prolongs motor life under adverse conditions

• Solid-state surface-mount technology increases reliability, offers excellent vibration resistance

and reduces heat generation

• Selectable 10/20/30 trip class offers flexibility for a range of applications