Technical data

March 2009
33-174
For more information visit: www.eaton.com CA08102001E
NEMA Contactors & Starters
33
A200
Relays — Thermal and Fast Trip, Product Family Overview
Contents
Description Page
Thermal and Fast Trip
Overload Relays
Product Family
Overview . . . . . . . . . . . . . . 33-174
Design Features . . . . . . . . . 33-174
Instruction Leaflets . . . . . . . 33-174
Thermal Type B, Class 20,
Manual Reset . . . . . . . . . . 33-175
Thermal Type A, Class 20,
Auto/Manual Reset . . . . . 33-177
Type FT Fast Trip,
Class 10 . . . . . . . . . . . . . . . 33-179
Heater Selection . . . . . . . . . 33-181
Type A Overload Relay
3-Pole Panel Mount
Product Family Overview
Type B and Type A, Class 20 Cutler-
Hammer
®
Thermal Overload Relays
from Eaton’s electrical business will
protect the motor against abnormal
overload conditions. Bimetallic actuated,
they are available as either ambient
compensated or non-compensated in
either single-pole or block type three-
pole design. The Type B use one pole of
the three-pole block for single-phase.
Single-pole relays are also available as
Fast Trip Class 10 ambient compen-
sated type, which provides approxi-
mately 125% motor protection with a
tripping time of less than 10 seconds,
at 600% of heater current rating.
Fast trip relays can be identified by the
green reset rods. They are available for
panel or starter mounting. The three-
pole fast trip design is composed of
three single-pole relays on a common
baseplate, with a common reset bar.
The bimetal element is actuated by
precisely calibrated heater elements
which are connected directly in the cir-
cuit to be protected. Thermal actuation
of this device opens the contacts in the
coil circuit of a contactor or relay
which results in the disconnection of
power to the overloaded circuit.
Interchangeable thermal heater ele-
ments for single-pole standard trip and
block type overload relays are avail-
able to cover motor full load currents
from .29 to 133A in approximately 10%
steps (see Heater Application Table).
Fast trip overload relays do not have
interchangeable heater elements but
are available in a series of ratings to
cover motor full load currents from 1.6
to 150A in approximately 50% steps.
Design Features
Manual or Automatic Reset
The Type B is furnished with a manual
reset. The Type A is normally fur-
nished set for manual reset operation
and may be quickly adjusted for auto-
matic reset when required. Automatic
reset should not be used with 2-wire
control or where automatic restarting
would endanger either personnel or
equipment.
Trip Indication
An immediate visible indication of trip
is provided on the overload relay.
When an overload occurs, which
causes the relay to operate, a trip indi-
cator projects out and thus shows pos-
itive visual indication of trip. The Type
B has a mechanical trip bar to manu-
ally check the NC contact operation on
the overload relay.
Adjustable Trip
On the Type A, the trip rating of a spe-
cific heater element can be adjusted
over a range of approximately 85% to
115% of its respective rating to permit
the desired close protection.
This is accomplished by turning the
adjusting knob on the relay to the
respective stop position.
Positive Contact Break
A follow-through contact, provided on
the stationary terminal of the snap
action control switch, provides reliable
electrical continuity during toggling,
thus eliminating false trip sometimes
prevalent with thermally operated
switches. This contact also allows con-
tact wipe for further reliability.
Ambient Compensation
Motor overload protection can be pro-
vided with the same trip characteris-
tics in ambient temperature from -40°
to 77°C (-40° to 167°F). A compensat-
ing bimetal maintains a constant
“travel to trip” distance independent
of ambient conditions. The compen-
sating feature is fully automatic and no
adjustments are required over wide
fluctuations in ambient temperatures.
Compensated relays are identified by
black reset rods on the Type A and
light gray reset rods on the Type B,
while non-compensated relays use red
reset rods. AA three-pole units have
gray reset rods. AA one-pole units
have black reset rods.
Control Contact
Single-pole and block type relays are
supplied as standard with a SPST NC
control contact. A SPDT NO-NC with
common is available as a factory mod-
ification on the Type A. An isolated NO
contact can be supplied on the Type B
as either a factory modification or as a
field kit.
Instruction Leaflets
14885B Fast Trip A Sizes 0 – 4,
3-Pole OL Relay
14567E Type A Sizes 1 – 2, 1-Pole
OL Relay Mod A
14568 Type A Sizes 1 – 2, 3-Pole
OL Relay Mod J
14570D Type A Sizes 3 – 4, 3-Pole
OL Relay Mod J
14569C Type A Sizes 3 – 4, 1-Pole
OL Relay Mod A
17093A Type B OLR for Sizes 7, 8
and 9 Contactors
16955A Type B Sizes 1 – 2, 1-Pole
OL Relay
16954A Type B Sizes 1 – 2, 3-Pole
OL Relay
15392B Type B Sizes 3 – 4, 3-Pole
OL Relay
13676F Fast Trip Sizes 0 – 4, 1-Pole
OL Relay