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
