Control Techniques Dynamic Braking Resistors Catalog Page

Dynamic Braking Resistors

Dynamic Braking (DB)

The DC bus voltage level of an AC drive increases while the
motor is re-generating (i.e. ramping to a stop). Dynamic braking
resistors provide a means of rapidly stopping a rotating motor
and load while maintaining an acceptable bus voltage level.
The kinetic energy stored in the spinning mass is converted
into electrical energy and quickly dissipated as heat through
a resistor.

Dynamic Braking for AC Drives

AC drives provide a constant torque stopping profile when
a dynamic brake resistor is applied across the DC bus circuit.
Dynamic braking can be employed under a stop command or
anytime a decrease in motor speed is commanded, provided
the AC drive is enabled and programmed for ramp stop (fast
ramp mode).

Two types of dynamic braking kits are available for Control
Techniques’ AC Drives. The E-stop duty kits are rated for light
start/stop or deceleration duty cycles.

The cyclic duty kits are intended for heavy duty applications
that need the capability to dissipate regenerated energy on a
more continuous or repetitive basis such as downhill conveyors,
hoists, feeders and dynamometers.

DB Resistors for AC Drives

Unidrive M drives are equipped with built-in dynamic braking
transistors. Simply select the proper braking resistor needed for
the size of drive and duty cycle. Other mounting arrangements
and enclosures are available on request.

The brake circuit must include an external thermal protection
device connected (as shown in the circuit diagram) unless the
resistor has built-in protection.

Galvanized NEMA 1 with
normally closed thermostat

E-Stop Duty

E-stop duty DB resistors are designed for absorbing energy
generated by infrequent motor stops or deceleration.

These kits are designed to meet or exceed NEMA
standard 7-15-1970, which states “DB resistors will not exceed
their rated temperature rise when the drive is braked from
maximum speed to standstill three times in rapid succession with
a load inertia equal to or less than the motor inertia.” They are
designed to provide 150% braking torque for 1800 rpm base
speed motors.

Cyclic Duty

The standard packages listed below are NEMA 1 rated and
include built-in junction box, terminal strip, normally closed
thermal contact (klixon switch) and resistors pre-wired with
high-temperature Teflon wire.

These heavy-duty kits have been designed to provide dynamic
braking for cyclic and continuous braking applications. There are
three levels available: 10%, 25% and 50%. These levels refer to
the continuous allowable braking level (i.e. 25% refers to 25%
of rated motor braking torque) or the maximum allowable duty
cycle rates with maximum specified “on-time” limitations (refer
to illustration below).

22

Dynamic Braking Resistors - 230 Vac

Galvanized NEMA 1 Enclosed

Dynamic Braking Resistors

E-Stop Duty

Drives

Duty

HP

Maaa-01100017 0.33 DBR-1500-00300-P 10 x 3 x 3 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4

Maaa-01100024 0.5 DBR-1500-00300-P 10 x 3 x 3 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4

Maaa-02100042 1 DBR-1500-00300-P 10 x 3 x 3 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00600-ENC 5 x 14 x 4

Maaa-02100056 1.5 DBR-1500-00300-P 10 x 3 x 3 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00600-ENC 5 x 14 x 4

Maaa-01200017 0.33 DBR-1500-00300-P 10 x 3 x 3 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4

Maaa-01200024 0.5 DBR-1500-00300-P 10 x 3 x 3 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4

Maaa-01200033 0.75 DBR-1500-00300-P 10 x 3 x 3 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4

Maaa-01200042 1 DBR-1500-00300-P 10 x 3 x 3 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00300-ENC 5 x 14 x 4 DBR-1500-00600-ENC 5 x 14 x 4

Maaa-02200024 0.5 DBR-0800-00300-P 10 x 3 x 3 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4

Maaa-02200033 0.75 DBR-0800-00300-P 10 x 3 x 3 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4

Maaa-02200042 1 DBR-0800-00300-P 10 x 3 x 3 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00600-ENC 5 x 14 x 7

Maaa-02200056 1.5 DBR-0800-00300-P 10 x 3 x 3 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00600-ENC 5 x 14 x 7

Maaa-02200075 2 DBR-0800-00300-P 10 x 3 x 3 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00300-ENC 5 x 14 x 4 DBR-0800-00600-ENC 5 x 14 x 7 DBR-0800-01500-ENC 5 x 14 x 13

Maaa-03200100 3 DBR-0800-00300-P 10 x 3 x 3 DBR-0500-00300-ENC 5 x 14 x 4 DBR-0500-00300-ENC 5 x 14 x 4 DBR-0500-01500-ENC 5 x 14 x 13 DBR-0500-01000-ENC 14 x 13 x 5

Maaa-04200133 3 DBR-0300-00400-P 12 x 3 x 1.5 DBR-0300-00400-ENC 5 x 14 x 4 DBR-0300-00600-ENC 5 x 14 x 7 DBR-0300-01500-ENC 5 x 14 x 4 DBR-0300-01500-ENC 5 x 14 x 4

Maaa-04200176 5 DBR-0300-00400-P 12 x 3 x 1.5 DBR-0200-00400-ENC 5 x 14 x 4 DBR-0200-00600-ENC 5 x 14 x 7 DBR-0200-01500-ENC 5 x 14 x 13 DBR-0200-03000-ENC 5 x 28 x 13

Mbbb-03200050 1 DBR-0500-00300-P 9 x 3 x 1.5 DBR-0500-00300-ENC 5 x 14 x 4 DBR-0500-00300-ENC 5 x 14 x 4 DBR-0500-00500-ENC 5 x 14 x 7 DBR-0500-01500-ENC 5 x 14 x 13

Mbbb-03200066 1.5 DBR-0500-00300-P 9 x 3 x 1.5 DBR-0500-00300-ENC 5 x 14 x 4 DBR-0500-00300-ENC 5 x 14 x 4 DBR-0500-00500-ENC 5 x 14 x 7 DBR-0500-01500-ENC 5 x 14 x 13

Mbbb-03200080 2 DBR-0500-00300-P 9 x 3 x 1.5 DBR-0500-00300-ENC 5 x 14 x 4 DBR-0500-00300-ENC 5 x 14 x 4 DBR-0500-00500-ENC 5 x 14 x 7 DBR-0500-01500-ENC 5 x 14 x 13

Mbbb-03200106 3 DBR-0500-00300-P 9 x 3 x 1.5 DBR-0400-00300-ENC 5 x 14 x 4 DBR-0400-00300-ENC 5 x 14 x 4 DBR-0350-01500-ENC 5 x 14 x 13 DBR-0350-01500-ENC 5 x 14 x 13

Mbbb-04200137 3 DBR-0300-00400-P 12 x 3 x 1.5 DBR-0200-00400-ENC 5 x 14 x 4 DBR-0200-00600-ENC 5 x 14 x 7 DBR-0200-01500-ENC 5 x 14 x 13 DBR-0200-01500-ENC 5 x 14 x 13

Mbbb-04200185 5 DBR-0300-00400-P 12 x 3 x 1.5 DBR-0200-00400-ENC 5 x 14 x 4 DBR-0200-00600-ENC 5 x 14 x 7 DBR-0200-01500-ENC 5 x 14 x 13 DBR-0200-03000-ENC 5 x 28 x 13

Mccc-05200250 7.5 DBR-0300-00400-P 12 x 3 x 1.5 DBR-0200-00400-ENC 5 x 14 x 4 DBR-0200-00600-ENC 5 x 14 x 7 DBR-0200-01500-ENC 5 x 14 x 13 DBR-0200-03000-ENC 5 x 28 x 13

Mccc-06200330 10

Mccc-06200440 15 DBR-0100-00600-ENC 5 x 14 x 7 DBR-0100-01200-ENC 5 x 14 x 10 DBR-0100-03000-ENC 5 x 21 x 13 DBR-0100-06000-ENC 7 x 29 x 18

Mccc-07200610 20 DBR-0055-02000-ENC 5 x 14 x 13 DBR-0055-02000-ENC 5 x 14 x 13 DBR-0055-04500-ENC 5 x 28 x 13 DBR-0055-09000-ENC 7 x 29 x 18

Mccc-07200750 25 DBR-0055-02000-ENC 5 x 14 x 13 DBR-0055-03000-ENC 5 x 21 x 13 DBR-0055-06000-ENC 7 x 29 x 18 DBR-0055-09000-ENC 7 x 29 x 18

Mccc-07200830 30 DBR-0055-02000-ENC 5 x 14 x 13 DBR-0055-03000-ENC 5 x 21 x 13 DBR-0055-06000-ENC 7 x 29 x 18 DBR-0055-12000-ENC 14 x 29 x 18

Mccc-08201160 40 DBR-0055-02000-ENC 5 x 14 x 13 DBR-0055-03000-ENC 5 x 21 x 13 DBR-0055-09000-ENC 7 x 29 x 18 DBR-0055-18000-ENC 14 x 29 x 18

Mccc-08201320 50 DBR-0055-02000-ENC 5 x 14 x 13 DBR-0055-04500-ENC 5 x 28 x 13 DBR-0055-12000-ENC 14 x 29 x 18 DBR-0055-18000-ENC 14 x 29 x 18

Mddd-09201760 60 DBR-0016-03000-ENC 5 x 21 x 10 DBR-0016-06000-ENC 5 x 28 x 13 DBR-0016-12000-ENC 16 x 29 x 18 DBR-0016-21000-ENC 23 x 29 x 18

Mddd-09202190 75 DBR-0016-03000-ENC 5 x 21 x 10 DBR-0016-06000-ENC 5 x 28 x 13 DBR-0016-15000-ENC 16 x 29 x 18 DBR-0016-27000-ENC 37 x 29 x 18

Meee-10202830 100 DBR-0022-05500-ENC 5 x 28 x 13 DBR-0022-12000-ENC 9 x 29 x 18 DBR-0022-21000-ENC 23 x 29 x 18 DBR-0022-48000-ENC 37 x 29 x 18

Meee-10203000 125 DBR-0022-05500-ENC 5 x 28 x 13 DBR-0022-12000-ENC 16 x 29 x 18 DBR-0022-27000-ENC 23 x 29 x 18 DBR-0022-48000-ENC 36 x 29 x 28

Heavy

Panel Mounted

No Thermostat

Order Code

H x W x D

N/A

Dims.

E-Stop Duty - NEMA 1

Normally Closed

Thermostat

(in)

Order Code

DBR-0100-00600-ENC 5 x 14 x 7 DBR-0100-00900-ENC 5 x 14 x 10 DBR-0100-03000-ENC 5 x 21 x 13 DBR-0100-04500-ENC 5 x 28 x 13

Dims.

H x W x D

(in)

10% Duty Rated
Normally Closed

Thermostat

Order Code

H x W x D

Dims.

(in)

25% Duty Rated
Normally Closed

Thermostat

Order Code

H x W x D

50% Duty Rated
Normally Closed

Thermostat

Dims.

Order Code

(in)

Dims.

H x W x D

(in)

23

aaa = Unidrive M100, M101, M200, M201, M300, HS30, M400
bbb = Unidrive M600, M700, M701, M702, HS70, HS71, HS72
ccc = Unidrive M200, M201, M300, M400, M600, M700, M701, M702, HS70, HS71, HS72
ddd = Unidrive M200, M201, M300, M400, M600, M700, M701, M702
eee = Unidrive M600, M700, M701, M702

Example: DBR-0400-00500-ENC is a 40.0 Ohm, 500 W Resistor, E = NEMA 1 Enclosure and NC = Normally Closed Thermostat
Standard resistor assemblies are not UL recognized. Consult factory for UL versions.