Control Techniques Commander SE Advanced User's Manual page 147

The information to be entered into parameters 10.30 Maximum full power braking time and 10.31 Maximum full power
braking period for the protection of these resistors is given in the following tables. It can be seen that the ON time at 780VDC
on certain resistor values* is too small to be entered into parameter 10.30. The range of parameter 10.30 is 0.0 to 400.0 in
100ms steps.
The following ON times will increase the resistor element up to a temperature of 400°C. The following 'duty cycles' keep the
resistor case temperature below the thermostat trip temperature of 160°C. If the following times and duty cycle are exceeded,
the resistor thermostat will open.
Resistor
Ω
15
20
30
40
50
75
100
150
Adiabatic ratings
These resistors have a low adiabatic rating. The adiabatic rating is the amount of heat the resistor element can withstand in a
single pulse without being damaged.
Maximum ON times
The following table gives the maximum ON times that the resistor can withstand without the element being damaged. The
table also gives the minimum OFF times before the next pulse to ensure that the resistor element does not get damaged and
also that the resistor case temperature does not exceed approx 160°C.
The following ON times will increase the resistor element up to a temperature of 800°C.
Resistor
Ω
15
20
30
40
50
75
100
150
NOTE
If these ON times are exceeded, the resistor will be damaged.
Alternative braking resistors
Alternative braking resistors can be sourced from the following braking resistor manufacturers:
Pentagon Electrical Products Ltd
www.pentagonelectric.co.uk
Cressall Resistors
www.cressall.com
REO
www.reo.co.uk
Commander SE Advanced User Guide
Issue Number: 4
T @ 390VDC T @ 390VDC T
ON OFF
ms s
110 32
135 29
199 25
218 23
343 23
249 18
438 18
479 15
T @ 390VDC T @ 390VDC T
ON OFF
ms s
220 56
270 51
398 42
436 40
686 41
497 31
876 31
959 26
@ 780VDC T @ 780VDC
ON OFF
ms s
28* 32
34* 29
50* 25
54* 23
86* 23
62* 18
109 18
120 15
@ 780VDC T @ 780VDC
ON OFF
ms s
55* 56
67* 51
99* 42
109 40
172 41
124 31
219 31
240 26
147