138 • vacon
BRAKE CHOPPER UNIT (NXB)
Tel. +358 (0)201 2121 • Fax +358 (0)201 212 205
9
Analogue input voltage
0…+10V, Ri = 200k
Ω
, (–10V…+10V joystick control)
Resolution 0.1%, accuracy ±1%
Analogue input current
0(4)…20 mA, Ri = 250
Ω
differential
Digital inputs (6)
Positive or negative logic; 18…30VDC
Auxiliary voltage
+24V, ±10%, max. 250mA
Output reference voltage
+10V, +3%, max. load 10mA
Analogue output
0(4)…20mA; RL max. 500
Ω
; Resolution 10 bit;
Accuracy ±2%
Digital outputs
Open collector output, 50mA/48V
Control con-
nections
Relay outputs
2 programmable change-over relay outputs
Switching capacity: 24VDC/8A, 250VAC/8A, 125VDC/0.4A
Min. switching load: 5V/10mA
Overvoltage trip limit
Undervoltage trip limit
NX_W5: 911VDC; NX_W6: 1200VDC
NX_W5: 333VDC; NX_W6: 461VDC
Overcurrent protection
Yes
Unit overtemperature
protection
Yes
Resistor overtemperature
protection
Yes
Wrong connection protec-
tion
Yes
Protections
Short-circuit protection of
+24V and +10V reference
voltages
Yes
Allowed cooling agents
Drinking water (see specification on page 39)
Water-glycol mixture
See derating specifications, chapter 5.3
Volume
See page 41.
Temperature of cooling
agent
0…35°C (I
br
)(input); 35…65ºC: derating required, see
Chapter 5.3
Max. temperature rise during circulation 5°C
No condensation allowed. See Chapter 5.2.1.
Cooling agent flow rates
See Table 5-6.
System max. working
pressure
6 bar
System max. peak pres-
sure
40 bar
Liquid cooling
Pressure loss (at nominal
flow)
Varies according to size. See Table 5-8.
Table 10-1. Technical specification for Vacon NXB liquid-cooled brake chopper unit