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 81
Revision T, September 28, 2022
4.4
Standard Features
4.4.1
Type of Power Conversion Circuit: High frequency.
4.4.2
Float Charging Output Mode: In this mode of operation, system output voltage is constant and output current
does not exceed the current limit setting. During normal operation, the battery is not required to furnish load
current and remains in a fully charged condition.
The float voltage setting can be checked and/or adjusted without removing a Rectifier Module or affecting the
load. One adjustment changes the output of all Rectifier Modules.
Note:
If the current demanded by the load exceeds the current limit setting of the system, the battery is
required to furnish the difference in load current and begins discharging.
Note:
If the system is used with a digital battery charge temperature compensation probe, the MCA
automatically adjusts system output. This ensures proper voltage to the battery as battery ambient
temperature fluctuates.
4.4.3
Test/Equalize Charging Output Mode: This mode of operation is used if higher output voltage is required for
equalizing the charge on all battery cells of a conventional flooded cell battery, or for recharging the battery
following a commercial power failure.
If the installation site does not require system equalize mode of operation, the equalize feature can be used as
a test feature. System equalize voltage can be adjusted to a test voltage value. Placing the system into the
test/equalize mode causes system output voltage to increase or decrease to this test voltage value.
The test/equalize voltage setting can be checked and/or adjusted without removing a Rectifier Module or
affecting the load. One adjustment changes the output of all Rectifier Modules.
Note:
If the system is used with a battery charge temperature compensation probe, typical equalize mode of
operation is not used.
4.4.4
Output Mode of Operation Selection: There are four methods of placing the system from the float mode to the
test/equalize mode.
(A)
Method 1 (Manual Test/Equalize): A user manually places the system into the test/equalize mode via the
MCA interface. A user must manually return the system to the float mode via the MCA interface.
(B)
Method 2 (Manually Initiated Timed Test/Equalize): A user manually places the system into the
test/equalize mode via the MCA interface. The system automatically returns to the float mode after a
preset programmable time period (1-99 hours, in increments of one hour).
(C)
Method 3 (Automatic Test/Equalize):
THE AUTOMATIC EQUALIZE FEATURE IS INTENDED FOR USE ONLY WITH WET CELL BATTERIES.
USING THIS FEATURE WITH VALVE REGULATED BATTERIES IS NOT RECOMMENDED.
This feature can be enabled or disabled by a user via the MCA. The default state is disabled.
The Automatic Equalize feature is a time based function that is controlled by a customer selectable
multiplier and by the Battery on Discharge (BOD) alarm setpoint. The MCA’s default setting is for a
multiplier of zero, which disables the Automatic Equalize feature.
When the Automatic Equalize feature is enabled, if system voltage drops to less than the BOD alarm
setpoint, the MCA initiates a timing cycle to measure the discharge time period. The MCA requires at
least 15 minutes of continuous BOD alarm in order to prevent nuisance equalization cycles. When
system voltage rises to above the BOD alarm setpoint, the MCA ends the discharge timing cycle and
(assuming a minimum of 15 minutes has elapsed) places the Rectifier Modules into the equalize mode
for a customer selectable multiple of the discharge time period (the discharge time period includes the
initial 15 minutes).
The equalize time period can be set for 0 to 15 times the discharge time period, up to a maximum of 300
hours. A zero (0) setting disables the feature.
(D)
Method 4 (External Test/Equalize): A user (or external equipment) places the system into the
test/equalize mode by applying an external signal to the system. The system returns to the float mode
when the external signal is removed. This method overrides the other three methods.
4.4.5
Input Protection: Lists 1 and 9 provide connections for twenty-four (24) AC input branch circuits (one per
Rectifier Module mounting position). Lists 2 and 10 provide connections for two (2) AC input branch circuits
(two per Power Bay). Customer to provide AC input branch circuit protection.
(A)
Input Over/Under Voltage Protection: The Rectifier Module shuts down and its protection indicator
(yellow) illuminates when the input voltage is lower than 260VAC or higher than 530VAC. This condition
is reported to the power system controller and the power system controller processes the alarms
accordingly.
