bonitron M3460, Customer Reference Manual

Page: 36 / 68

D_M3460_D_CMAN_vall_00a 4/17/2020
36
4.8.1. D
ETERMINING THE
DC B
US
T
HRESHOLD
V
OLTAGE
S
ETTING
D
IRECTLY
(M3460R M
ODELS
)
Checking the DC bus threshold voltage setting directly requires the AC power
to be removed from the M3460R. If the M3460R DC bus is not connected to
the output of the drive, this can be done without powering down the drive.
Otherwise, the drive must have the AC power removed from it as well. It may
be difficult to get an accurate reading using a digital voltmeter due to the time
it takes to calculate and average the reading. Use an analog meter if possible.
1. Monitor the output DC bus of the M3460R, or the input DC bus to the
drive, if connected.
2. Remove input voltage supply from system.
3. As the DC bus voltage drops to the DC bus threshold voltage setting,
the M3460R will become active and maintain the DC bus voltage at the
threshold voltage setpoint for approximately 1 second while the
M3460R input filter capacitor discharges. The DC bus will then continue
to drop.
4. Read the DC bus voltage as it is being maintained. This is the DC bus
threshold voltage setting.
4.8.2. D
ETERMINING THE
DC B
US
T
HRESHOLD
V
OLTAGE
S
ETTING
D
IRECTLY
(M3460B M
ODELS
)
Checking the DC bus threshold voltage setting directly requires disconnecting
the M3460B DC bus from the drive DC bus while the battery bank supplies
power to the M3460B.
1. Monitor the output DC bus of the M3460B.
2. Disconnect the M3460B DC bus from the drive DC bus.
3. The M3460B should now be active and the voltage at the M3460B
output DC bus is the threshold setting.
4.8.3. D
ETERMINING THE
DC B
US
T
HRESHOLD
V
OLTAGE
S
ETTING
U
SING THE
T
EST
M
ODE
The DC bus threshold voltage setting may be checked with the drive connected
using the test input to put the M3460 in Test mode. This raises the DC bus
voltage approximately 50-100V above the actual DC bus threshold voltage
setting, and is a fair indication of how the system is set. This has the advantage
of not having to remove the AC power, and can actually be done while the
system is loaded.
Please note:
•
If heavily loaded, the M3460 may run in current limit and the DC bus voltage
may not rise as much as if it were unloaded.
•
If the DC bus threshold voltage is set too high, the DC bus test voltage may
be limited by the overvoltage setting of the M3460, thus providing an
inaccurate result.
The M3460 may shutdown from the timeout feature, depending on the load.
1. Monitor the output DC bus of the M3460, or the input DC bus to the
drive, if connected.
2. Initiate a test with the display.