NORD Drivesystems BU0230 - Manual (Page 43)

3 Assembly and installation
BU 0230 GB-2712 43
3.5 Safe pulse block
A two-wire shielded cable must be used for the safe pulse block. The shield must be connected at on both
ends. For mechanical switching devices the line drop in the cable must not exceed
ΔU
Cable
≤ 3 V and for
electronic protective switching devices it must not exceed ΔU
Cable
≤ 1 V. The peak current I
IN,Peak
= 500 mA for
Sizes 1 to 3 or I
IN,Peak
= 500 mA for size 4 should be used for the calculation.
Input voltages: 24 V

25 % = 18 V … 30 V
(24V SH – GND SH) 24 V - 20 % +25 % = 19.2 V … 30 V for operation with OSSD
Size 1 to 3:
125 mA (AV)
500 mA (Peak) after switching-on or after a test pulse from an OSSD
Size 4:
40 mA (AV)
250 mA (Peak) after switching-on or after a test pulse from an OSSD
3.5.1 Details of the safe pulse block
Terminal/
Name
Function
[factory setting]
Data Description / wiring suggestion Parameter
SK 210, SK 215E, SK230 and SK 235E
89 24V SH 24V input for the
safe pulse block 18…30 V,
125 mA (Size 1 to 3)
40mA (Size 4)
See technical data
Fail-safe input -
88 GND SH Reference potential
for the safe pulse block
0 V, reference potential
3.5.2 Operation at OSSD
The safe pulse block is specially designed for use with an OSSD.
The capacity between the wires (including the shielded capacities) must not exceed a value of 20nF for each
inverter connected.
Additional restrictions may apply here with regard to the protective switching device.
3.5.3 Multi-device operation
When operating several inverters on one protective switching device, the switching capacity of the switching
device and the load rating of the 24 V power-feeding supply must be observed.
The shield must be applied to all inverters.
The permissible line drops on the cable must be observed!
Example:
o 4x frequency inverter at an electronic protective switching device!
o The 4x FIs are arranged next to each other in a system.
o 20 m must be bridged between the FI and the switching device!
o Shielded cable 2x1.5 mm
2
q
l
R
CU
*
 
with
km
mm
CU
2
* 19
  
Double the length of cable must be used because line drops occur in both wires.
 
5 , 0 R
V A I Number R U
Peak IN FU Cable
1 5 . 0 * 4 * 5 . 0 * *
,
    
=> OK!