Brake Resistor Calculator
Instructions for use
Enter the Minimum Brake Resistor Ohms
required by the inverter. Leave the Watts entry blank (or enter a value
if you prefer to reduce the options). The calculator will list
the best combinations of resistors and connection arrangements. Select a 'Watts
Continuous Rating' and 'Connection Option' that suits your application. For higher
resistance combinations and overload details see 'Selecting the Correct Dynamic
Brake Resistor' below.
| Order Code |
Qty |
Connection |
Resistance (Ohms) |
Continuous Load (Watts) |
Total Price |
|
| 19582 |
1 |
As it is |
100.00 |
100.00 |
£10.00 |
|
| 19137 |
2 |
Parallel |
100.00 |
200.00 |
£20.00 |
|
| 19875 |
4 |
Parallel |
125.00 |
240.00 |
£32.00 |
|
| 19536 |
2 |
Series |
112.00 |
400.00 |
£36.00 |
|
| 19875 |
5 |
Parallel |
100.00 |
300.00 |
£40.00 |
|
| 19582 |
4 |
2 x 2 in series, then pairs in parallel |
100.00 |
400.00 |
£40.00 |
|
| 22840 |
2 |
Series |
120.00 |
240.00 |
£60.00 |
|
| 21281 |
2 |
Series |
112.00 |
1,000.00 |
£72.00 |
|
| 24086 |
1 |
As it is |
100.00 |
1,500.00 |
£75.00 |
|
| 19137 |
8 |
4 x 2 in series, then pairs in parallel |
100.00 |
800.00 |
£80.00 |
|
| 21020 |
3 |
Series |
108.00 |
1,500.00 |
£108.00 |
|
| 23697 |
2 |
Series |
120.00 |
200.00 |
£126.05 |
|
| 19536 |
8 |
2 x 4 in series, then strings in parallel |
112.00 |
1,600.00 |
£144.00 |
|
| 23993 |
2 |
Series |
100.00 |
3,000.00 |
£150.00 |
|
| 20073 |
5 |
Series |
110.00 |
1,500.00 |
£155.00 |
|
| 22840 |
8 |
2 x 4 in series, then strings in parallel |
120.00 |
960.00 |
£240.00 |
|
| 21281 |
8 |
2 x 4 in series, then strings in parallel |
112.00 |
4,000.00 |
£288.00 |
|
| 24086 |
4 |
2 x 2 in series, then pairs in parallel |
100.00 |
6,000.00 |
£300.00 |
|
| 20576 |
1 |
As it is |
100.00 |
4,500.00 |
£313.00 |
|
| 23697 |
8 |
2 x 4 in series, then strings in parallel |
120.00 |
800.00 |
£504.19 |
|
| 20817 |
5 |
Series |
110.00 |
10,000.00 |
£535.00 |
|
| 23993 |
8 |
2 x 4 in series, then strings in parallel |
100.00 |
12,000.00 |
£600.00 |
|
| 20132 |
2 |
Series |
100.00 |
9,000.00 |
£626.00 |
|
| 20273 |
4 |
Series |
112.00 |
12,000.00 |
£804.00 |
|
| 20509 |
2 |
Series |
100.00 |
15,000.00 |
£816.00 |
|
| 20884 |
2 |
Series |
100.00 |
22,000.00 |
£1,164.00 |
|
| 20393 |
4 |
Series |
112.00 |
18,000.00 |
£1,252.00 |
|
| 20576 |
4 |
2 x 2 in series, then pairs in parallel |
100.00 |
18,000.00 |
£1,252.00 |
|
| 20618 |
2 |
Series |
100.00 |
24,000.00 |
£1,376.00 |
|
| 19314 |
4 |
Series |
112.00 |
24,000.00 |
£1,632.00 |
|
| 19895 |
7 |
Series |
105.00 |
31,500.00 |
£2,191.00 |
|
| 20852 |
4 |
Series |
112.00 |
36,000.00 |
£2,328.00 |
|
| 19895 |
8 |
Series |
120.00 |
36,000.00 |
£2,504.00 |
|
| 20132 |
8 |
2 x 4 in series, then strings in parallel |
100.00 |
36,000.00 |
£2,504.00 |
|
| 19602 |
4 |
Series |
112.00 |
48,000.00 |
£2,752.00 |
|
| 21072 |
8 |
2 x 4 in series, then strings in parallel |
100.00 |
48,000.00 |
£3,264.00 |
|
| 20509 |
8 |
2 x 4 in series, then strings in parallel |
100.00 |
60,000.00 |
£3,264.00 |
|
| 21132 |
4 |
Series |
112.00 |
72,000.00 |
£3,732.00 |
|
| 20709 |
4 |
Series |
112.00 |
90,000.00 |
£3,732.00 |
|
| 22456 |
8 |
Series |
108.80 |
76,800.00 |
£4,656.00 |
|
| 20884 |
8 |
2 x 4 in series, then strings in parallel |
100.00 |
88,000.00 |
£4,656.00 |
|
| 20241 |
7 |
Series |
105.00 |
84,000.00 |
£4,816.00 |
|
| 20241 |
8 |
Series |
120.00 |
96,000.00 |
£5,504.00 |
|
| 20618 |
8 |
2 x 4 in series, then strings in parallel |
100.00 |
96,000.00 |
£5,504.00 |
|
| 20815 |
7 |
Series |
105.00 |
126,000.00 |
£6,531.00 |
|
| 20815 |
8 |
Series |
120.00 |
144,000.00 |
£7,464.00 |
|
Selecting the Correct Dynamic Brake Resistor
Satisfy only two criteria to size Dynamic Brake resistors:-
1) Match the resistors to the drive by entering the Minimum External Resistance
in our calculator to suit the drive. This is shown in the drive details on this site.
The Inverter Manufacturer lists the Minimum resistance or resistance range
in the product manuals.
2) Total Resistor Power; is decided by the energy to be returned from the load and the motor size. Rule of thumb is - a typical
horizontal conveyer or similar load required to stop occasionally and can stop
in less than 2.5 seconds at full braking, will need a resistor continuous power
just less than 10% of motor power. Just less, means a small allowance for the mechanical
losses that help brake the load.
High braking loads and/or frequent stops will
need to be calculated or estimated to suit the energy returning and the resistor
power selected. Contact us
if you need help with this.
Prices and connection options of the most effective combinations are worked out
for you in our Resistor Calculator above.
Notes:
To size the kW rating of the resistors - follow these three simple rules.
The small aluminium resistors
1) For Brake times of 25 seconds and over, continuously rate the resistors at the
power returning from the load - see note (a).
2) For braking times below 25 seconds, take the average power to be dissipated in
the busiest 25 seconds.
3) Do not exceed 10 x the resistor continuous kW rating during any overload period,
however short.
The larger caged resistors
1) For Brake times of 120 seconds and over, continuously rate the resistors at the
power returning from the load - see note (b).
2) For braking times below 120 seconds, take the average power to be dissipated
in the busiest 120 seconds.
3) Do not exceed 10 x the resistor continuous kW rating during any overload period,
however short.
Temperature:
(a) The small Aluminium clad resistors take 25 secs to reach normal maximum working
temperature when absorbing rated power continuously.
(b) The larger Caged resistors take 120 secs to reach normal maximum working temperature
when absorbing rated power continuously.
WARNING!
- A lower resistance than recommended will pass excessive current and will damage the Inverter.
- The Minimum Resistance can be exceeded, but if the resistor
value is excessively high, reduced braking will result.
- Insufficient total resistor
Watts will result in high resistor temperatures.