Wenglorz - Dipl. Ing. Helmut Wenglorz GmbH

Elektronische Thyrisor-Bremsgeräte Reihe BGT

Technical Documentation DC Braking Equipment
BGD and BGT Overview > main data
Technical data BGD 1 to 4 BGT 31 BGT 35, BGT 40
Nominal voltage UN + 20% < = 400 VAC < = 500 VAC < = 500 VAC
Power supply UH = ± 20% 230 VAC 230 VAC 230, 400, 500 VAC
Frequency from UN and UH 40-60 Hz 40-60 Hz 40-60 Hz
Max power consumption 3 VA 3,2 VA 4,0 VA

Max braking current IB max

10 bis 40 A 25 A 35 - 350 A, larger braking currents on request
Display for braking current IB7, segment, 3-dec. ---- ---- optional BGT 35 > ab 110 A
Setting-range of braking current ---- 10 - 100% 10 - 100%
Braking initiation Contact initiating Contactinitating Contact initating
Safety time until braking-start      
a) Time-dependent 100ms 100ms 120ms
b) EMF dependent ---- ---- EMF drop-out time + 120ms
EMF switching value     dependent on nominal voltage
  • at 500 VAC factory adjusted to
---- ---- 250 V
  • at 230 to 400 VAC factory adjusted to
---- ---- 150 V
Duty ratio 50% 50% 50%
Braking time tB      
  • Setting on the unit
0,5-5 s 0,8-10 s 0,8-15 s
  • external setting
---- ---- 0,6-60s
Relay output 1 CO contact 1 CO contact 1 CO contact
    Contact voltage / contact current
250 VAC / 8 A 250 VAC / 8 A 250 VAC / 8 A (B213xH245xT145)
  • Switching power (ohmic load)
1250 VA / 150 W 1250 VA / 150 W 1250 VA / 150 W (B213xH381xT175)
Ambient temperature 0 - 55°C 0 - 55°C 0 - 55°C
Braking equiment      
  • consistings of
2 units 1 unit 1 unit
Protection according to DIN 40050 (STandard) IP 40 / IP00 IP40 IP10
Weight 0,25 / 0,25 kg 0,5 kg BGT 35 up to 70A > 1kg bis 150A 1,2 kg
      BGT 35 up to 150A with IB display > 2,5 kg
      BGT 40 up to 250A with IB display > 2,5 kg
      BGT 40 up to 350A with IB display > 3,5 kg
Mounting: screwing-on (S) or on-top-hat rail (H) S or H S or H S
housing Standard / open frame standard housing  
  open frame    
Einbaulage cooling fins vertical ---- cooling fins vertical
Dimensions Width x Height x Depth (mm) control unit ----  
  • Control unit
  • Diode unit

50 x 75 x 115

50 x 75 x 145

IB = 35 - 70A B170xH85xT107----
IB =150A B175xH90xT115----
IB = 200-250A  B215xH245xT145
IB = 300-450A  B215xH381xT175
Planning notes
When selecting a DC braking unit it shall be based on that the permis- sible data of the complete drive system during start-up do not exceed the data during braking with regard to the thermal and mechanical loads. There are two fundamentally different methods for selecting of a DC braking device, a mathematical and graphical method, Despite many simplifications (e.g. neclect of the leakage inductance and saturation change of the motor) both methods are complicated and time consuming without a computer based program. Another problem is also that in practice only rarely all necessary data and characteristics are available for the selecting. In general following considerations are suffient for selecting of a DC braking unit. 1. It must be known: nominal motor voltage, nominal motor current, motor circuit at start-up and braking 2. The nominal motor voltage is taken into account by the device manufacturer in selection of the power semiconductors regarding their repetitive peak off-state voltage 3 To determine the braking current the approximate equation IB = c x IN is valid. In the factor c the relationship between DC average value, which determines among other things the braking torque of the engine, and RMS current is provided; the RMS current is decisive for dimensioning of brake unit. Also included are above mentiones considerations when comparing the 3AC feed-in and DC feed-in. In consideration of the factor c - depending on the choosen circuit - results an applicable DC current in general.
Motor circuitStarDeltaDelta
Braking circuitStarDeltaStar
Very high frequencies of operation and special motors with resi- stances of the stator winding different from standard values require a more precise calculation; for that purpose it is necessary to get exact informations about frequencies of operation and stator winding. A control program in the brake unit ensures, that the brake con- tactor is switched only in no-load condition; the brake contactor does not switch the brake current, only it transfers the brake current (see functional diagram). For the selection of contactor as approximate value: Current Ith of contactor is approximately equal to the braking current.

For the protection of semiconductors may only semiconductor fuses (e.g. types silized, ultrarapid) be used. Slow-blow fuses are not allowed According to our proposals circuit it is very important to ensure a safety interlock between line contactor and brake contactor. In general in extreme cases (e.g. very high frequencies of operation, large braking torque) the engine is more at risk than the Wenglorz-brake equipment.