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 Rating Total Price In Stock  
19582 1 As it is 100Ω
100W
£11.00
24501 1 As it is 100Ω
60W
£17.00
20679 1 As it is 100Ω
200W
£20.00
24503 2 Parallel 100Ω
120W
£30.00
24505 3 Parallel 110Ω
180W
£42.00
19582 4 2 x 2 in series, then pairs in parallel 100Ω
400W
£44.00
24545 1 As it is 100Ω
300W
£49.00
19536 2 Series 112Ω
400W
£50.00
19875 4 Parallel 125Ω
240W
£52.00
24551 1 As it is 100Ω
500W
£61.00
24512 3 Parallel 110Ω
300W
£63.00
22840 2 Series 120Ω
240W
£64.00
24501 4 2 x 2 in series, then pairs in parallel 100Ω
240W
£68.00
24534 2 Parallel 110Ω
400W
£68.00
24542 2 Parallel 110Ω
600W
£78.00
20679 4 2 x 2 in series, then pairs in parallel 100Ω
800W
£80.00
24514 4 Parallel 125Ω
400W
£84.00
21281 2 Series 112Ω
1kW
£88.00
24801 1 As it is 100Ω
1kW
£89.00
24086 1 As it is 100Ω
1.5kW
£92.00
24543 2 Parallel 100Ω
600W
£96.00
23697 2 Series 120Ω
200W
£100.80
24538 3 Series 120Ω
600W
£102.00
24539 3 Series 108Ω
600W
£102.00
24527 5 Parallel 120Ω
500W
£105.00
24503 8 4 x 2 in series, then pairs in parallel 100Ω
480W
£120.00
24541 3 Parallel 110Ω
900W
£132.00
24547 3 Series 120Ω
900W
£132.00
24532 4 Parallel 125Ω
800W
£136.00
24804 2 Series 100Ω
2kW
£168.00
24531 5 Parallel 120Ω
1kW
£170.00
24526 4 Parallel 125Ω
1.2kW
£176.00
24803 2 Series 112Ω
2kW
£178.00
24024 2 Series 120Ω
2kW
£178.00
24548 3 Parallel 110Ω
1.5kW
£180.00
24553 3 Series 120Ω
1.5kW
£183.00
25964 2 Parallel 100Ω
3kW
£184.00
24814 2 Series 120Ω
3kW
£184.00
24822 2 Series 100Ω
4kW
£190.00
24545 4 2 x 2 in series, then pairs in parallel 100Ω
1.2kW
£196.00
19536 8 2 x 4 in series, then strings in parallel 112Ω
1.6kW
£200.00
21020 3 Series 108Ω
1.5kW
£219.00
26008 1 As it is 100Ω
4.5kW
£220.00
24535 8 4 x 2 in series, then pairs in parallel 100Ω
1.6kW
£248.00
22840 8 2 x 4 in series, then strings in parallel 120Ω
960W
£256.00
24805 3 Series 108Ω
3kW
£267.00
24534 8 4 x 2 in series, then pairs in parallel 110Ω
1.6kW
£272.00
24529 8 Parallel 125Ω
1.6kW
£272.00
24554 5 Series 110Ω
2.5kW
£275.00
24815 3 Series 108Ω
4.5kW
£276.00
24823 3 Series 108Ω
6kW
£285.00
24830 2 Series 100Ω
6kW
£310.00
24542 8 4 x 2 in series, then pairs in parallel 110Ω
2.4kW
£312.00
24557 4 Series 112Ω
800W
£312.00
26052 2 Series 100Ω
9kW
£322.00
21281 8 2 x 4 in series, then strings in parallel 112Ω
4kW
£352.00
24824 4 Series 108Ω
8kW
£380.00
24543 8 4 x 2 in series, then pairs in parallel 100Ω
2.4kW
£384.00
23697 8 2 x 4 in series, then strings in parallel 120Ω
800W
£403.20
24806 5 Series 110Ω
5kW
£445.00
24831 3 Series 108Ω
9kW
£452.76
24818 5 Series 110Ω
7.5kW
£460.00
24825 5 Series 110Ω
10kW
£475.00
24807 6 Series 114Ω
6kW
£534.00
23461 5 Series 100Ω
10kW
£535.00
24819 6 Series 114Ω
9kW
£551.88
24826 6 Series 114Ω
12kW
£570.00
24832 4 Series 108Ω
12kW
£620.00
24808 7 Series 105Ω
7kW
£623.00
23461 6 Series 120Ω
12kW
£642.00
24837 4 Series 108Ω
16kW
£644.00
24820 7 Series 105Ω
10.5kW
£644.00
24827 7 Series 105Ω
14kW
£665.00
24804 8 2 x 4 in series, then strings in parallel 100Ω
8kW
£672.00
24808 8 Series 120Ω
8kW
£712.00
24803 8 2 x 4 in series, then strings in parallel 112Ω
8kW
£712.00
25964 8 4 x 2 in series, then pairs in parallel 100Ω
12kW
£736.00
24827 8 Series 120Ω
16kW
£760.00
24822 8 2 x 4 in series, then strings in parallel 100Ω
16kW
£760.00
24833 5 Series 110Ω
15kW
£795.00
24838 5 Series 110Ω
20kW
£805.00
20273 4 Series 112Ω
12kW
£812.00
20509 2 Series 100Ω
15kW
£816.00
26008 4 2 x 2 in series, then pairs in parallel 100Ω
18kW
£880.00
24834 6 Series 114Ω
18kW
£930.00
24839 6 Series 114Ω
24kW
£966.00
24840 7 Series 105Ω
28kW
£1,127.00
20884 2 Series 100Ω
22kW
£1,164.00
24860 5 Series 110Ω
30kW
£1,195.00
24830 8 2 x 4 in series, then strings in parallel 100Ω
24kW
£1,240.00
20393 4 Series 112Ω
18kW
£1,264.00
24840 8 Series 120Ω
32kW
£1,288.00
26052 8 2 x 4 in series, then strings in parallel 100Ω
36kW
£1,288.00
24861 6 Series 114Ω
36kW
£1,434.00
19314 4 Series 112Ω
24kW
£1,632.00
24044 6 2 x 3 in series, then strings in parallel 120Ω
30kW
£1,738.14
24863 7 Series 105Ω
49kW
£2,135.00
27667 7 Series 112Ω
56kW
£2,142.00
19895 7 Series 105Ω
31.5kW
£2,212.00
20852 4 Series 112Ω
36kW
£2,328.00
24863 8 Series 120Ω
56kW
£2,440.00
19895 8 Series 120Ω
36kW
£2,528.00
19602 4 Series 112Ω
48kW
£2,752.00
20509 8 2 x 4 in series, then strings in parallel 100Ω
60kW
£3,264.00
21072 8 2 x 4 in series, then strings in parallel 100Ω
48kW
£3,264.00
20709 4 Series 112Ω
90kW
£3,732.00
21132 4 Series 112Ω
72kW
£3,732.00
22456 8 Series 108.8Ω
76.8kW
£4,656.00
20884 8 2 x 4 in series, then strings in parallel 100Ω
88kW
£4,656.00
20241 7 Series 105Ω
84kW
£4,816.00
20241 8 Series 120Ω
96kW
£5,504.00
20618 8 2 x 4 in series, then strings in parallel 100Ω
96kW
£5,504.00
20815 7 Series 105Ω
126kW
£6,531.00
20815 8 Series 120Ω
144kW
£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!

  1. A lower resistance than recommended will pass excessive current and will damage the Inverter.
  2. The Minimum Resistance can be exceeded, but if the resistor value is excessively high, reduced braking will result.
  3. Insufficient total resistor Watts will result in high resistor temperatures.