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Size 1 or 2 Type A Thermal Overload 

Relay, 3 Pole, Ambient Compensated 

or Non-Compensated

The relay

The Type A thermal overload relay (OLR) is a 

bimetallic device which, with the properly selected 

wire and heaters, will provide motor protection 

for running and stalled rotor overloads in motor 

circuits not exceeding 600 volts. The Size 1 and 2 

OLR’s have a maximum current rating of 26.2 and 

45.0 amperes respectively. Ambient compensated 

OLR’s are readily distinguishable by light gray reset 

rods. Non-ambient compensated OLR’s have red 

reset rods.

Operation

The strip bimetals in the OLR are indirectly heated 

by the replaceable heater elements (Item 4 in 

Figure 1) which carry the motor current. Excess 

heat is generated in these heater elements by an 

overloaded motor. The heated bimetals deflect to 

open the normally closed (NC) contact, thereby 

opening the coil circuit of a magnetic contactor 

which disconnects the overloaded motor from the 

line. After approximately 2 minutes, the relay (if 

hand reset) may be reset by pressing the reset 

rod. For relays in the auto position, resetting 

occurs automatically.

Installation

The OLR must be installed on a vertical surface 

with the control terminals at the bottom. The relay 

is accurately calibrated at the factory and should 

not be tampered with. Installation should be made 

with the proper wire size (

see heater selection 

table

) for the application and all wires must be 

securely fastened. Preferably, the OLR should be 

located in the same ambient as the motor to be 

protected and in an area free of drafts. Heater 

elements are supplied separately and must be 

properly selected and securely mounted. Three 

heaters must be used for either single or three 

phase applications.
This industrial type control is designed to be 

installed, operated, and maintained by adequately 

trained workmen. These instructions do not cover 

all details, variations, or combinations of the 

equipment, its storage, delivery, installation, check 

out, safe operation, or maintenance. Care must be 

exercised to comply with local, state, and national 

regulations, as well as safety practices, for this 

class of equipment.

Control circuit contacts

The normally closed (NC) control circuit contact 

is to be connected in series with the coil of a 

magnetic contactor. This NC contact is equipped 

with a follow contact which provides reliable 

electrical continuity during a tripping condition. A 

factory installed normally open (NO) control circuit 

contact (single pole double throw - Form C) is 

available for remote trip indication applications. AC 

contact ratings are listed in 

Table 2

.

Table 1.  Catalog number

Type

Panel mounted

A200 controller 

mounted

Size 1

Size 2

Size 

00-0-1

Size 2

Ambient 

Compensated

AA13P

AA23P

AA13A

AA23A

Non-ambient 

Compensated

AN13P

AN23P

AN13A

AN23A

Figure 1. Size 1 overload relay for panel 

mounting

For NO/NC contacts add suffix B

Instruction Leaflet 

IL14568

Effective June 2020 
Supersedes April 1984

Summary of Contents for AA13P

Page 1: ...ction table for the application and all wires must be securely fastened Preferably the OLR should be located in the same ambient as the motor to be protected and in an area free of drafts Heater elements are supplied separately and must be properly selected and securely mounted Three heaters must be used for either single or three phase applications This industrial type control is designed to be i...

Page 2: ...40oF to 167oF Because of a compensating bimetal which maintains a constant travel to trip distance independent of ambient conditions operation of this bimetallic relay is responsive only to heat generated by the motor overcurrent passing through the heater element The compensating feature is fully automatic and no adjustments are required over normal fluctuations in ambient temperatures Overload r...

Page 3: ...ired in their secondary circuits supplying current to the Type G heaters Wire the second ary circuits of the current transformers with 12 or 14 conductors Divide the motor full load current by the transformer turns ratio to determine the equivalent motor fullload current and select the appro priate heater from Table 5 for a service factor 1 15 medium voltage motor Table 5 Type G heaters Code Marki...

Page 4: ...rrent listed for each heater Eaton 1000 Eaton Boulevard Cleveland OH 44122 United States Eaton com 2018 Eaton All Rights Reserved Printed in USA Publication No IL14568 002 June 2020 Eaton is a registered trademark All other trademarks are property of their respective owners Size 1 or 2Type AThermal Overload Relay 3 Pole Ambient Compensated or Non Compensated Instruction Leaflet IL14568 Effective J...

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