Vertiv
™
NetSure
™
-48 VDC Power System
System Application Guide
Spec. No: 582140001
Proprietary and Confidential © 2022 Vertiv Group Corp.
SAG582140001
Model No: 801
NLDB
, 801
NLEB
, 801
NL
-
B
Page 73
Revision T, September 28, 2022
(B)
Input Fusing: Input fusing is provided in each Rectifier Module. This fusing is not customer replaceable.
3.4.6
Output Protection
(A)
Current Limiting: The maximum current delivered by the system can be programmed from 10% to 110% of
total system capacity. The MCA automatically adjusts the current limit circuit on each Rectifier Module so
that this value is not exceeded. If a Rectifier Module fails, the MCA automatically resets each remaining
Rectifier Module's current limit point to maintain this value. The MCA also insures that the current limit
circuit on any Rectifier Module is not set above 110% of its capacity. The default current limit setting is
the sum of each installed Rectifier Module's output rating. If an additional Rectifier Module is added to the
system, the system current limit is automatically increased by the rating of the new Rectifier Module and
the new current limit value is displayed.
The current limiting point can be adjusted without removing a Rectifier Module. One adjustment changes
the setting of all Rectifier Modules.
The current limit is factory set at 100% of rated full load, unless otherwise specified.
(B)
Output Fusing: Output fusing is provided in each Rectifier Module. If a fuse opens, local and remote
Rectifier Module Fail Alarms activate. This fusing is not customer replaceable.
(C)
High Voltage Shutdown
(1)
Internal: If Rectifier Module output voltage exceeds an adjustable preset value, the Rectifier Module
shuts down.
After approximately 5 seconds, the Rectifier Module automatically restarts. If Rectifier Module
output voltage again exceeds the high voltage shutdown value within 5 minutes, the Rectifier
Module shuts down and locks out. Manual restart is then required. If the Rectifier Module does not
experience a high voltage condition within the 5 minute time period, the restart circuit is reset.
If two or more Rectifier Modules are installed in the Power Bay, or if the Power Bay is paralleled with
other Power Bays, only the Rectifier Module causing the high voltage condition shuts down.
The high voltage shutdown point can be checked and/or adjusted without removing a Rectifier
Module. One adjustment changes the setting of all Rectifier Modules.
Adjustable from 56.0 to 59.0 volts DC. Factory set at 57.50 volts, unless otherwise specified.
(2)
Remote: See Paragraph 4.1.14 (B).
(3)
Backup: If Rectifier Module output voltage exceeds a second (non-adjustable) value, the Rectifier
Module shuts down and locks out regardless of load. Manual restart is then required. The fixed
hardware HVSD is 59.5V (within the range of 58.5 to 60V).
3.4.7
High Temperature Protection:
(A)
When the PFC board temperature is higher than 85°C, the rectifier turns off. When the PFC board
temperature is lower than 75°C, the rectifier resumes to normal operation, and the hysteresis is at least
10°C.
(B)
When the “ambient temperature – PFC board temperature” is higher than 5°C, the rectifier turns off.
When the “ambient temperature – PFC board temperature” is lower than 2°C, the rectifier resumes to
normal operation, and the hysteresis is at least 3°C.
(C)
When the DC board temperature is higher than 105°C, the rectifier turns off. When the DC board
temperature is lower than 95°C, the rectifier resumes to normal operation, and the hysteresis is at least
10°C.
3.4.8
Fan Fault Protection: An alarm will be generated upon a fan fault. In such cases, the fault indicator (red) on
the Rectifier Module front panel will flash and the Rectifier Module will also inhibit its output. Auto-recovery is
enabled upon the clearing of the corresponding fault.
3.4.9
PFC Over/Under Voltage: The rectifier will shut down when its bus voltage is higher than the over voltage set
point or is lower than the under voltage set point. During such conditions, the rectifier does not output any
power and its protection indicator (yellow) will light up.
3.4.10
Load Sharing (via MCA): The MCA load sharing feature automatically balances the load. If the MCA's load
sharing feature is disabled for any reason, pre-programmed slope control in each Rectifier Module balances the
load. The MCA's load sharing feature is disabled whenever the system is in current limit, the system is
delivering more than 97% capacity, or the system is delivering less than 3% capacity.
Active Load Sharing (Rectifier Module): The Rectifier Module uses advanced digital active load sharing
technology that maintains balancing to within ±3A. The difference in the average current between rectifiers is
<±3A for loads in the 10 to 100% range.
