Minarik NRGD-4Q Series, User Manual

Page: 32 / 80

20 Installation
Regen dump circuit connections
The external regen dump circuit reduces the voltage across the
bus capacitor when it reaches a factory-set trip point.
As the drive regeneratively brakes, it returns excess voltage to the
bus capacitor, where it is stored until it can be discharged. When
the regen dump circuit detects excess bus voltage, it redirects or
“dumps” the excess voltage through a shunt resistor network,
safely discharging the bus capacitor. Bus capacitor maximum
working voltage ratings are 200 VDC for 120 VAC drives and
400 VDC for 240 VAC drives.
Please contact your Minarik representative for more information
on changing the dump circuit’s regen dump trip setting. Refer to
Figure 8, page 21, for regen dump circuit connections.
Table 2. Regen Dump Circuit Part Numbers
NRGD Drive
Line Input Voltage
Drive model number 120 VAC 240 VAC
NRGDxx–D240AC–4Q BOSS DB-115* BOSS DB-230*
*Because the BOSS-DB is powered by the drive’s bus voltage,
the BOSS DB-230 regen dump circuit requires a line voltage of
240 VAC. Use BOSS DB-115 if line voltage is 120 VAC.
Warning
Minarik strongly recommends the installation of an extenal
regen dump circuit if you plan to use regenerative braking.
This will help avoid damage to the motor or drive.
250-0281.qxd 4/4/01 11:16 AM Page 20