Powerohm Instruction
Manual for Type PW-NC
High Current Braking
Modules
Part Numbers Covered:
PWA450NC, PWA600NC, PWA900NC, PWA1200NC
PWB450NC, PWB600NC, PWB900NC, PWB1200NC
PWC450NC, PWC600NC, PWC900NC, PWC1200NC
PWD450NC, PWD600NC, PWD900NC, PWD1200NC
PWE450NC, PWE600NC, PWE900NC, PWE1200NC
Technical Assistance: +01-859-384-8088
IMPORTANT: These instructions should be read thoroughly before installation. All
warnings and precautions should be observed for both personal safety and for proper
equipment performance and longevity. Failure to follow these instructions could result in
equipment failure and/or serious injury to personnel. Braking modules contain lethal
voltages when connected to the inverter. It is very important to remove power to the
inverter before installing or servicing this unit. Always allow adequate time (approximately
5 minutes) after removing power before touching any components. The LED’s must be
completely out before servicing the unit.
product Overview
AC variable frequency drives are commonly used with general purpose AC
induction motors to form reliable variable speed drive systems.
Problems with these drive systems can occur when an application
requires a deceleration rate faster than what can be managed by the
drive alone, or when motor speeds exceed the synchronous speed set
by the output frequency of the drive (which is called an overhauling load
condition). Both of these conditions create regenerated power which
flows from the motor back into the drive, causing its DC Bus to rise. To
manage the regenerated power and avoid shutting the drive down due to
an over-voltage trip, this power must be dissipated by an external
braking resistor.
Powerohm Type BM Braking Modules can be used in conjunction with any
AC drive to monitor the DC bus of the drive and activate external
braking resistor as needed not only to avoid over-voltage trips, but to
greatly improve the performance of the drive system. The use of Braking
Modules and resistors increase the braking torque capability of a
variable frequency drive, allowing faster and more controlled
deceleration times.
To accommodate system horsepower requirements beyond the capability of
a single Module, the Modules are all Master/Slave programmable. This
allows an arrangement of multiple Modules to effectively function as a
single higher rated module.
Technical Assistance: +01-859-384-8088
Inspection upon Receipt
Upon receipt of your Powerohm Braking Module, be sure to carefully unpack the module
and inspect the unit carefully for any shipping damage. The module contains electronics
that can be damaged by static electricity, so handle in accordance with industry standards.
Check for loose, broken or otherwise damaged parts due to shipping. Report any shipping
damage immediately to the freight carrier. Be sure to verify that the part number and ratings
listed on the nameplate match the order specification and the capabilities of the drive
system. The ratings listed on the nameplate are critical – installing and energizing
the incorrect part number could damage the braking module and/or the drive!
Environmental Conditions
The Powerohm Type BM Braking Module should be installed in an environment
protected from moisture and excessive dust. Dust buildup can reduce the electrical
insulation characteristics of the unit and moisture can cause arching or shorting. Air
must be free of combustible gases and corrosive vapors.
Ambient Temperature Range: -10ºC to 40ºC
Maximum Altitude: 3300 feet (1000m)
Electrical Ratings
The Powerohm Type BM Braking Module is available in line voltages ranging from 208
to 720 volts. Peak currents up to the maximum are allowed at intermittent duty
cycles (reference the below tables for details).
TABLE 1: General Specifications for 450 amp Type BM Braking Modules
Powerohm
Part
Number
Nominal
AC Line
Voltage
PWA-450NC
240
450
375
600
PWB-450NC
480
450
750
600
PWC-450NC
600
450
940
600
PWD-450NC
690
450
1090
600
PWE-450NC
720
450
1120
600
RMS Continuous Turn ON
Load Current
Voltage
Max Peak
Current
Technical Assistance: +01-859-384-8088
TABLE 2: General Specifications for 600 amp Type BM Braking Modules
Powerohm
Part
Number
Nominal
AC Line
Voltage
PWA-600NC
240
600
375
900
PWB-600NC
480
600
900
PWC-600NC
600
600
750
940
PWD-600NC
690
600
1090
900
PWE-600NC
720
600
1120
900
RMS Continuous Turn ON
Load Current
Voltage
Max Peak
Current
900
TABLE 3: General Specifications for 900 amp Type BM Braking Modules
Powerohm
Part
Number
Nominal
AC Line
Voltage
PWA-900NC
240
900
375
1350
PWB-900NC
480
900
750
1350
PWC-900NC
600
900
940
1350
PWD-900NC
690
900
1090
1350
PWE-900NC
720
900
1120
1350
RMS Continuous Turn ON
Load Current
Voltage
Max Peak
Current
TABLE 4: General Specifications for 1200 amp Type BM Braking Modules
Powerohm
Part
Number
Nominal
AC Line
Voltage
RMS Continuous Turn ON
Load Current
Voltage
Max Peak
Current
PWA-1200NC
240
1200
375
1800
PWB-1200NC
480
1200
750
1800
PWC-1200NC
600
1200
940
1800
PWD-1200NC
690
1200
1090
1800
PWE-1200NC
720
1200
1120
1800
Technical Assistance: +01-859-384-8088
Equipment Installation
The Powerohm Type BM Braking Module should be installed on a low vibration surface
that is non-flammable.
Maximum Vibration: 10 to 20Hz, 32ft/sec/sec; 20 to 50Hz, 6.5 ft/sec/sec
Attention:
Installation and removal of this equipment should be done by
qualified personnel only. Equipment must be installed in accordance with all
applicable national and local electrical codes and regulations.
MOUNTING REQUIREMENTS
To allow proper cooling, it is very important to install the fan cooled Powerohm braking
modules in an ambient not exceeding 40 degrees Celsius or below 0 degrees
Celsius. Modules should be installed in an environment with sufficient circulation of
clean, dry air. The module should be installed in an area allowing a minimum of 6
inches of free space above and below the frame to allow proper airflow and cooling.
Technical Assistance: +01-859-384-8088
DIMENSIONS FOR 450 AMP AND 600 AMP MODULES
DC POWER CONNECTIONS
Remove this protective cover to access both the
DC bus and braking resistor connections.
W
CONTR OL POWER
DC BUS
BRAKE AC TIVE
CONTR OL ENABLED
FAU LT
POWEROHM BRAKING MODULE
19.00
20.00
20.00
DANGER: HIGH VOLTAGE
Braking module contains lethal voltages when
connected to the inverter. Power to the inverter must
be removed before servicing the braking module.
Allow adequate time (approximately 5 minutes ) after
removing power before touching any components.
Both the CONTROL POWER and DC BUS indicators
must be completely out before servicing the unit.
CONTROL POWER CONNECTIONS
Remove this protective cover to access all
control power and logic connections.
5.00
7.13
5/16 SLOTS
10.00
10.00
7.13
Weight: The weight of the unit is approximately 30 lbs.
Technical Assistance: +01-859-384-8088
DIMENSIONS FOR 900 AMP AND 1200 AMP MODULES
DC POWER CONNECTIONS
Remove this protective cover to access both the
DC bus and braking resistor connections.
W
POWEROHM BRAKING MODULE
CONTROL POWER
DC BUS
BRAKE ACTIVE
23.00
24.00
24.00
CONTROL ENABLED
FAULT
DANGER: HIGH VOLTAGE
Braking module contains lethal voltages when
connected to the inverter. Power to the inverter must
be removed before servicing the braking module.
Allow adequate time (approximately 5 minutes) after
removing power before touching any components.
Both the CONTROL POWER and DC BUS indicators
must be completely out before servicing the unit.
CONTROL POWER CONNECTIONS
Remove this protective cover to access all
control power and logic connections.
7.00
10.06
7/16 SLOTS
10.00
10.00
10.06
Weight: The weight of the unit is approximately 55 lbs.
Technical Assistance: +01-859-384-8088
WIRING RECOMMENDATIONS
It is recommended that the AC drive manual, braking resistor instructions and any other
pertinent documentation be thoroughly reviewed before proceeding. Note that
control and power wiring should be separated to avoid electrical noise and
interference problems. The wiring between the drive and braking module should
not exceed 15 feet and between the braking resistor and braking module should not
exceed 30 feet. Important: Always properly ground each module to earth. If
possible, ground Braking Module to AC Drive Module Power ground.
Figure 3: Wiring Lengths Between Drive System Components
DC POWER CONNECTIONS
Remove this protective cover to access both the
DC bus and braking resistor connections.
W
CONTROL POWER
DC BUS
BRAKE ACTIVE
CONTROL ENABLED
FAU LT
POWEROHM BRAKING MODULE
DANGER: HIGH VOLTAGE
Braking module contains lethal voltages when
connected to the inverter. Power to the inverter must
be removed before servicing the braking module.
Allow adequate time (approximately 5 minutes) after
removing power before touching any components.
Both the CONT ROL POWER and DC BUS indicators
must be completely out before serv ic ing the unit.
CONTROL POWER CONNECTIONS
DC+
DC-
Remove this protective cover to access all
control power and logic connections.
30 ft. max
15 ft. max
WARNING:
Never install a braking resistor directly across the DC bus of the
drive. Drive damage or failure may occur upon applied power. Additionally,
without the braking module to activate and deactivate the braking resistor, the
resistor will dissipate power continuously and be subject to overheating and
failure.
Technical Assistance: +01-859-384-8088
POWER CONNECTIONS
The Powerohm Type BM Braking Module features a total of five power connections.
Reference Table 5 for a description of each terminal’s function.
ATTENTION:
The National Electric Code (NEC) and local regulations govern
the installation and wiring of electrical equipment such as braking resistors and
modules. DC power wiring, AC power wiring, control wiring and conduit must be
installed in accordance with all applicable codes and regulations.
TABLE 5: Description of Power Connections
Max.Torque
Terminal
Terminal Description
(lb-ft) for
Number
450A/600A
Max.Torque
(lb-ft) for
900A/1200A
DC -
DC Bus Connection (Negative)
20
50
DC+
DC Bus Connection (Positive)
20
50
G
Ground Connection
6
50
RES
Braking Resistor Connection
20
50
RES
Braking Resistor Connection
20
50
Technical Assistance: +01-859-384-8088
CONTROL CONNECTIONS
The Powerohm Type BM Braking Module features three terminal blocks for all input,
output and control power wiring. All three terminal blocks are located at the bottom
of the braking module, above the fan compartment and accept 30 to 14 gage wire.
The outputs are located on TB1 featuring 16 poles. The inputs are located on TB2
featuring 12 poles. The control power (115VAC) terminations are located on TB3
featuring 2 poles. Reference Tables 6, 7 and 8 for a description of all terminations.
TABLE 6: OUTPUT TERMINATIONS
Terminal
Number
Maximum
Torque (lb-in)
Terminal Description (TB1)
1
Control Enabled
2.2
2
Control Enabled
2.2
3
Power Section Ready
2.2
4
Power Section Ready
2.2
5
Master Slave Status
2.2
6
Master Slave Status
2.2
7
Instantaneous Over Current Protection (IOC)
2.2
8
Instantaneous Over Current Protection (IOC)
2.2
9
IOV/ IUV
2.2
10
IOV/ IUV
2.2
11
OT
2.2
12
OT
2.2
13
SUPPLY VALID
2.2
14
SUPPLY VALID
2.2
15
IGBT SHORTED
2.2
16
IGBT SHORTED
2.2
The Output Contacts are rated 170mA maximum (250VAC or DC).
Technical Assistance: +01-859-384-8088
TABLE 7: INPUT TERMINATIONS
Terminal
Number
Maximum
Torque (lb-in)
Terminal Description (TB2)
1
Enable
2.2
2
Common
2.2
3
Master or Slave Select
2.2
4
Common
2.2
5
IOC/ IOV, IUV Reset
2.2
6
Common
2.2
7
DC Bus Discharge
2.2
8
Common
2.2
9
Signal +IN/ OUT
2.2
10
Signal +IN/ OUT
2.2
11
Signal Common
2.2
12
Signal Common
2.2
The Inputs are activated via contact closure. Contacts should be rated at 10mA
(24VDC).
TABLE 8: CONTROL POWER TERMINATIONS
Terminal
Number
Terminal Description (TB3)
Maximum
Torque (lb-in)
1
115VAC Input Power
2.2
2
115VAC Input Power
2.2
The control power input requires 115VAC (1.0 amp).
Technical Assistance: +01-859-384-8088
MINIMUM RECOMMENDED TB2 INPUT CONNECTIONS USED
WITH OPTIONAL COMMUNICATION MODULES (PROFIBUS,
ETHERNET, DEVICENET, ETC.)
ENABLE
1
2
CLOSE
TO
ENABLE
MASTER/ SLAVE
SELECT
3
4
CLOSE
TO
SELECT
MASTER
FAULT
RESET
5
DISCHARGE
6
PUSH
TO
RESET
7
8
CLOSE
TO
DISCHARGE
NOTE: DISCHARGE INPUT FUNCTIONS ONLY IN MASTER MODE.
WARNING:
It is important to check the DC Bus Voltage before servicing a
braking module. Do not fully rely upon the DC Bus Discharge feature as an
absolute means of discharging the DC Bus.
Technical Assistance: +01-859-384-8088
TYPICAL MASTER SLAVE TB2 WIRING CONNECTIONS
9
MASTER
SLAVE
SLAVE
SIGNAL
SIGNAL
SIGNAL
10
11
12
9
10
11
12
9
10
11
12
CONTINUES TO
OTHER SLAVES
IF PRESENT
SIGNAL
NOTE: Braking modules should be no closer together than 6 inches to allow for
adequate cooling. Interconnecting wiring should not exceed 5 feet between modules.
Technical Assistance: +01-859-384-8088
TYPICAL MASTER SLAVE FIBER OPTIC CONNECTIONS
MASTER
SLAVE
SLAVE
FIBER
OPTIC
FIBER
OPTIC
FIBER
OPTIC
TX
RX
TX
RX
TX
RX
CONTINUES TO
OTHER SLAVES
IF PRESENT
TABLE 9: FIBER OPTIC SPECIFICATIONS
Component
Specification
Maximum
Torque (lb-in)
CABLE
1mm plastic, 60 ft. maximum length
9
CONNECTOR
SMA (Threaded Connection Type)
9
NOTE: Slave will produce a TX pulse even if fed from the Master or previous Slave via
copper signal connections.
Technical Assistance: +01-859-384-8088
Optional communication modulES
– profibus & ETHERNET
COMMUNICATION MODULE INPUTS AND OUTPUTS
TABLE 10: COMMUNICATION MODULE INPUTS
Input
Description
1
Enable
2
Master or Slave Select
3
Fault Reset
4
DC Bus Discharge
TABLE 11: COMMUNICATION MODULE OUTPUTS
Output
Description
1
Control Enabled
2
Power Section Ready
3
Master Slave Status
4
Instantaneous Over Current Protection (IOC)
5
IOV/ IUV
6
OT
7
SUPPLY VALID
8
IGBT SHORTED
Technical Assistance: +01-859-384-8088
Note: Reference appropriate Phoenix Contact Instruction Manual available through
Powerohm or online at phoenixcontact.com.
OPTIONAL INLINE PROFIBUS COUPLER
Technical Assistance: +01-859-384-8088
CONNECTING TO THE PROFIBUS MODULE
Technical Assistance: +01-859-384-8088
OPTIONAL INLINE ETHERNET/IP BUS COUPLER
Technical Assistance: +01-859-384-8088
CONNECTING TO THE OPTIONAL ETHERNET MODULE
Technical Assistance: +01-859-384-8088
Technical Assistance: +01-859-384-8088
Module Setup
JUMPER SETTINGS
The Powerohm Type BM Braking Module has eight jumper settings located on the main
control board that are accessible by removing the center front cover that contains
the LED indicators. The 8 position program jumper is located in the top right corner
of the main control board. The jumper allows for a wide range of drive input
voltages as listed in Table 12. Note that the measurement of line voltage should be
done by qualified personnel only. Do not make jumper changes while the power is
applied! Note: Generally speaking, it is best to operate the module with the
highest allowable jumper setting to allow for upward drift of the AC line
during lightly loaded conditions. This will minimize the possibility of the
upward drift causing unnecessary action from the braking module.
TABLE 12 Description of Jumper Settings
Jumper Position
Line Voltage
DC Bus Voltage
1
208VAC
336VDC
2
240VAC
390VDC
3
380VAC
612VDC
4
415VAC
670VDC
5
480VAC
775VDC
6
600VAC
970VDC
7
690VAC
1090VDC
8
710VAC
1120VDC
Warning: Do not make jumper changes while power is applied! Change as required
only when power is removed and the green power indicator and amber dc bus
indicator is off!
Technical Assistance: +01-859-384-8088
Module Setup
Power Connections for a Single Braking Module
Braking Resistor
Braking Module
A.C. Drive
L1
THERMAL SWITCH
TO DRIVE LOGIC
DC POWER CONNECTIONS
L2
Remove this protective cover to access both the
DC bus and braking resistor connections.
L3
W
CO NTR OL POW ER
DC BUS
BRAKE ACTIVE
CO NTR OL ENABL ED
FAULT
RES
RES
POWEROHM BRAKING MODULE
T1
DANGER: HIGH VOLTAGE
B raking module contains lethal voltages when
connected to the inverter. Power to the inverter m ust
be removed before servicing the braking module.
Allow adequate time ( approxim ately 5 minutes) after
r emoving power before touching any c omponents.
B oth the CONTROL P OWE R and DC BUS indic ators
m ust be com pletely out before ser vicing the unit.
T2
AC
MOTOR
T3
CONTROL POWER CONNECTIONS
DC+
DC-
Remove this protective cover to access all
control power and logic connections.
Wiring Notes: All DC power wiring between the drive, braking module and braking
resistor should be twisted (if possible) and run separate from all control wiring. All
control wiring must be twisted and run separate from all power wiring.
Technical Assistance: +01-859-384-8088
Power Connections for Multiple Braking Modules
Braking Resistor
Braking Module
A.C. Drive
L1
THERMAL SWITCH
TO DRIVE LOGIC
DC POWER CONNECTIONS
L2
Re move t his pr ot ect ive co ve r to ac ces s bo th the
D C b us an d b ra kin g r es isto r c on ne ction s.
L3
W
CO NTRO L POW ER
DC BUS
BRAKE ACTIVE
CO NTRO L ENABLED
FAUL T
RES
RES
POWEROHM BRAKING M ODULE
T1
DANG ER: HIGH VOLT AG E
Brakin g mod ule con tains leth al voltage s wh en
c onnect ed to the inve rter. Po wer to the inve rter must
b e rem oved befor e ser vicing the b raking modu le .
Allow ad equa te time (app roxima tely 5 m in utes) after
r emoving power befor e tou ching a ny comp onen ts.
Both the CONT RO L POWER an d DC BUS indicat ors
m ust be complet ely out b efor e servicing the u nit.
T2
AC
MOTOR
T3
CONTROL POWER CONNECTIONS
DC+
DC-
R emov e th is p ro te ctive c ov er to a cce ss a ll
con tr ol p ow er an d log ic co nn ec tion s.
THERMAL SWITCH
TO DRIVE LOGIC
DC POWER CONNECTIONS
Re move t his pr ot ect ive co ve r to ac ces s bo th the
D C b us an d b ra kin g r es isto r c on ne ction s.
W
CO NTRO L POW ER
DC BUS
BRAKE ACTIVE
CO NTRO L ENABLED
FAUL T
RES
RES
POWEROHM BRAKING M ODULE
DANG ER: HIGH VOLT AG E
Brakin g mod ule con tains leth al voltage s wh en
c onnect ed to the inve rter. Po wer to the inve rter must
b e rem oved befor e ser vicing the b raking modu le .
Allow ad equa te time (app roxima tely 5 m in utes) after
r emoving power befor e tou ching a ny comp onen ts.
Both the CONT RO L POWER an d DC BUS indicat ors
m ust be complet ely out b efor e servicing the u nit.
CONTROL POWER CONNECTIONS
R emov e th is p ro te ctive c ov er to a cce ss a ll
con tr ol p ow er an d log ic co nn ec tion s.
THERMAL SWITCH
TO DRIVE LOGIC
DC POWER CONNECTIONS
Re move t his pr ot ect ive co ve r to ac ces s bo th the
D C b us an d b ra kin g r es isto r c on ne ction s.
W
CO NTRO L POW ER
DC BUS
BRAKE ACTIVE
CO NTRO L ENABLED
FAUL T
RES
RES
POWEROHM BRAKING M ODULE
DANG ER: HIGH VOLT AG E
Brakin g mod ule con tains leth al voltage s wh en
c onnect ed to the inve rter. Po wer to the inve rter must
b e rem oved befor e ser vicing the b raking modu le .
Allow ad equa te time (app roxima tely 5 m in utes) after
r emoving power befor e tou ching a ny comp onen ts.
Both the CONT RO L POWER an d DC BUS indicat ors
m ust be complet ely out b efor e servicing the u nit.
CONTROL POWER CONNECTIONS
R emov e th is p ro te ctive c ov er to a cce ss a ll
con tr ol p ow er an d log ic co nn ec tion s.
Master - Slave Settings: In the example above, the top braking module is set as
the Master and the lower two modules are in Slave Mode.
Wiring Notes: All DC power wiring between the drive, braking module and braking
resistor should be twisted (if possible) and run separate from all control wiring.
All control wiring must be twisted and run separate from all power wiring.
Spacing: Braking modules should be no closer than 6 inches to allow for adequate
cooling.
Technical Assistance: +01-859-384-8088
LED INDICATORS
The Powerohm Type BM Braking Module has five LED indicators on the front panel
that allow the user to verify the following:
CONTROL POWER: An illuminated green LED indicates that control power is
applied to the braking module.
DC BUS: An illuminated amber LED indicates that DC bus voltage is present
BRAKE ACTIVE: An illuminated red LED indicates that the module is braking.
CONTROL ENABLE: An illuminated green LED indicates that the control has been
enabled.
FAULT: An illuminated red LED can indicate any number of possible system faults.
Refer to Table 6 and check the status of all outputs to help identify the problem.
Likewise, if using a communications module, refer to Table 11 to check the status of
the outputs.
Technical Assistance: +01-859-384-8088