Schneider Electric A1.99 Thermal Unit Class 20 Plug-in

Product Description

The SCHNEIDER ELECTRIC A1.99 is a plug-in thermal overload unit designed for use in AC magnetic motor starters. It operates as a melting alloy thermal overload heater element and provides Class 20 standard trip protection for motor circuits. Motor full-load ampere (FLA) ratings vary by configuration: 1.78 to 1.92 amps with one thermal unit installed, 1.73 to 1.84 amps with two thermal units, and 1.59 to 1.72 amps with three thermal units. Licensed electricians and industrial maintenance technicians install this component as part of motor starter assemblies in both commercial and light industrial applications. It ships in a standard package of six units.

The A1.99 thermal unit is suited for AC magnetic starter applications where motor overload protection is required. All thermal unit selections are based on operation of the motor and controller in the same ambient temperature of 40 degrees C or less. If motor full-load current is not known at time of selection, a tentative thermal unit choice can be made based on motor horsepower and voltage rating. This unit carries an 18-month warranty and is manufactured in the United States under the Square D brand family within the Series A product line.

Key Features

• Class 20 standard trip type for motor overload protection
• Plug-in mounting for straightforward installation in compatible AC magnetic starters
• Melting alloy design — ratchet wheel must engage the pawl assembly for proper operation
• FLA range of 1.78 to 1.92 amps (single unit), 1.73 to 1.84 amps (two units), 1.59 to 1.72 amps (three units)
• All selections based on same-ambient-temperature operation at 40 degrees C or less
• 18-month warranty; manufactured in the United States

Compatibility

Designed for use on AC magnetic starters. Compatible with Type S, Type A, and Type M starter configurations as noted in the manufacturer catalog description. All thermal unit selections must match the starter model and ambient conditions before placing the motor into service.

Installation Notes

Installation should be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and all applicable local codes. Disconnect and lock out all power to the motor starter before installing or replacing thermal units. Verify that the correct thermal unit selection is installed for the actual motor FLA before energizing the starter. On melting alloy units, confirm the ratchet wheel is fully engaged with the pawl assembly before closing the starter enclosure.

Technical Specifications

• Trip Class: Class 20, Standard
• Motor FLA (1 Thermal Unit): 1.78 to 1.92 amps
• Motor FLA (2 Thermal Units): 1.73 to 1.84 amps
• Motor FLA (3 Thermal Units): 1.59 to 1.72 amps
• Mounting: Plug-In
• Used On: AC Magnetic Starter
• Standard Package Quantity: 6
• Length: 2.262 inches
• Width: 1.092 inches
• Height: 0.78 inches
• Weight: 0.04 pounds
• Ambient Temperature Rating: 40 degrees C or less
• Warranty: 18 months
• Country of Origin: United States

Standard Information

• Brand: SCHNEIDER ELECTRIC
• Manufacturer Part Number: A1.99