Vertiv NetSure 5100 Series User manual

NetSure™ 5100 Series
-48 VDC Power System
User Manual (UM582137200), Revision G
Specification Number: 582137200
Model Number: 5100

Vertiv |NetSure™ 5100 Series -48 VDC Power System User Manual (UM582137200)|Rev. G
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The information contained in this document is subject to change without
notice and may not be suitable for all applications. While every precaution
has been taken to ensure accuracy and completeness herein, Vertiv Group
Corp. assumes no responsibility, and disclaims all liability, for damages
resulting from use of this information or for any errors or omissions. Refer
to other local practices or building codes as applicable for the correct
methods, tools, and materials to be used in performing procedures not
specifically described in this document.
This document may contain confidential and/or proprietary information of
Vertiv Group Corp., and its receipt or possession does not convey any right
to reproduce, disclose its contents, or to manufacture or sell anything that
it may describe. Reproduction, disclosure, or use without specific
authorization from Vertiv Group Corp. is strictly prohibited.
Vertiv and the Vertiv logo are trademarks or registered trademarks of
Vertiv Group Corp. All other names and logos referred to are trade names,
trademarks or registered trademarks of their respective owners.
© 2019 Vertiv Group Corp. All rights reserved.

Vertiv |NetSure™ 5100 Series -48 VDC Power System User Manual (UM582137200)|Rev. G
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TABLE OF CONTENTS
Admonishments Used in this Document............................................................4
Important Safety Instructions ..............................................................................5
General Safety ...........................................................................................................................................................5
Voltages...........................................................................................................................................................................5
AC Input Voltages........................................................................................................................................................ 5
DC Output and Battery Voltages .................................................................................................................. 5
Battery .............................................................................................................................................................................. 6
Personal Protective Equipment (PPE)..............................................................................................7
Hazardous Voltage...............................................................................................................................................7
Handling Equipment Containing Static Sensitive Components..............................7
Maintenance and Replacement Procedures...............................................................................7
Static Warning...........................................................................................................8
Customer Documentation Package.....................................................................9
System Description..................................................................................................9
Operating Procedures...........................................................................................10
Controller and Rectifier .................................................................................................................................10
ESTOP Function...................................................................................................................................................10
Controller Battery Charge Current Limit Feature ................................................................11
Local Controls and Indicators..................................................................................................................11
Maintenance .............................................................................................................11
System Maintenance Procedures........................................................................................................11
Adding a Rectifier.................................................................................................................................................11
Installing a Field Expansion Rectifier Shelf ................................................................................ 12
Troubleshooting and Repair................................................................................ 18
Contact Information..........................................................................................................................................18
Controller and Rectifier .................................................................................................................................18
Controller Configuration...............................................................................................................................18
System Troubleshooting Information .............................................................................................18
Replacement Information............................................................................................................................19
Replacement Procedures............................................................................................................................19
Replacing a Rectifier............................................................................................................................................... 19
Replacing the NCU Controller....................................................................................................................... 19
Replacing a Distribution Device................................................................................................................. 20
Circuit Card Replacement Procedures.................................................................................................22

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ADMONISHMENTS USED IN THIS DOCUMENT
DANGER
! Warns of a hazard the reader will be exposed to that will likely result
in death or serious injury if not avoided. (ANSI, OSHA)
WARNING
! Warns of a potential hazard the reader may be exposed to that could
result in
death or serious injury if not avoided. This admonition is not used for situations that pose a
risk only to equipment, software, data, or service. (ANSI)
CAUTION
! Warns of a potential hazard the reader may be exposed to that could
result in minor or moderate injury if not avoided. (ANSI, OSHA) This admonition is not
used for situations that pose a risk only to equipment, data, or service, even if such use
appears to be permitted in some of the applicable standards. (OSHA)
ALERT
! Alerts the reader to an action that must be avoided in order to protect
equipment, software, data, or service. (ISO)
ALERT
! Alerts the reader to an action that must be performed in order to prevent
equipment damage, software corruption, data lo
ss, or service interruption. (ISO)
FIRE SAFETY
! Informs the reader of fire safety information, reminders, precautions,
or policies, or of the locations of fire
-fighting and fire-safety equipment. (ISO)
SAFETY
! Informs the reader of general safety information, reminders, precautions, or
policies not related to a particular source of hazard or to fire safety. (ISO, ANSI, OSHA)

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IMPORTANT SAFETY INSTRUCTIONS
General Safety
DANGER! YOU MUST FOLLOW APPROVED SAFETY PROCEDURES.
Performing the following procedures may expose you to hazards. These procedures should be
performed by qualified technicians familiar with the hazards associated with this type of equipment.
These hazards may include shock, energy, and/or burns. To avoid these hazards:
a) The tasks should be performed in the order indicated.
b) Remove watches, rings, and other metal objects.
c) Prior to contacting any uninsulated surface or termination, use a voltmeter to verify that no voltage
or the expected voltage is present. Check for voltage with both AC and DC voltmeters prior to
making contact.
d) Wear eye protection.
e) Use certified and well maintained insulated tools. Use double insulated tools appropriately rated for
the work to be performed.
Voltages
AC Input Voltages
DANGER! This system operates from AC input voltage capable of producing fatal electrical shock. AC
input power must be completely disconnected from the branch circuits wiring used to provide power to
the system before any AC electrical connections are made. Follow local lockout/tagout procedures to
ensure upstream branch circuit breakers remain de-energized during installation. DO NOT apply AC
input power to the system until all electrical connections have been completed and checked.
DC Output and Battery Voltages
DANGER! This system produces DC power and may have a battery source connected to it. Although
the DC voltage is not hazardously high, the rectifiers and/or battery can deliver large amounts of current.
Exercise extreme caution not to inadvertently contact or have any tool inadvertently contact an output
terminal or battery terminal or exposed wire connected to an output terminal or battery terminal.
NEVER allow a metal object, such as a tool, to contact more than one termination or battery terminal at a
time, or to simultaneously contact a termination or battery terminal and a grounded object. Even a
momentary short circuit can cause sparking, explosion, and injury.
DANGER! Follow local lockout/tagout procedures to ensure DC branch circuit protection devices
remain de-energized during installation at loads, as required.

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Battery
Refer to the battery manufacturer documentation for specific battery safety instructions. The following are
general guidelines.
WARNING! Correct polarity must be observed when connecting battery leads.
WARNING! Special safety precautions are required for procedures involving handling, installing, and
servicing batteries. Observe all battery safety precautions in this manual and in the battery instruction
manual. These precautions should be followed implicitly at all times.
WARNING! A battery can present a risk of electrical shock and high short circuit current. Servicing of
batteries should be performed or supervised only by properly trained and qualified personnel
knowledgeable about batteries and the required precautions.
The following precautions should be observed when working on batteries:
•Remove watches, rings, and other metal objects.
•Eye protection should be worn to prevent injury from accidental electrical arcs.
•Use certified and well maintained insulated tools. Use double insulated tools appropriately rated for
the work to be performed. Ensure that wrenches with more than one working end have only one
end exposed.
•Do not lay tools or metal parts on top of batteries.
•Verify that no current will flow when the battery is connected or disconnected by opening battery
disconnects (if available) or adjusting the system to match battery voltage.
•Risk of explosion if battery is replaced with an incorrect type or if polarity is reversed.
Recommended to replace batteries with the same manufacturer and type, or equivalent.
•Dispose of used batteries according to the instructions provided with the batteries. Do not dispose
of batteries in a fire. They may explode.
•ALWAYS FOLLOW THE BATTERY MANUFACTURER’S RECOMMENDATIONS AND SAFETY
INSTRUCTIONS.
DANGER! This equipment may be used in conjunction with lead-acid batteries. Working near lead-acid
batteries is dangerous!
In addition to the hazard of electric shock, gas produced by batteries can be explosive and sulfuric acid
can cause severe burns.
•Do not open or mutilate batteries. Released electrolyte is harmful to the skin and eyes, and is toxic.
•Batteries contain sulfuric acid.
•Batteries generate explosive gases during normal operation. Systems containing batteries should
never be installed in an airtight room or space. Only install in a ventilated environment.
•Batteries are an energy source that can produce high amounts of electrical current.

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FOR THESE REASONS, IT IS OF CRITICAL IMPORTANCE THAT YOU READ THESE INSTRUCTIONS
AND FOLLOW THEM EXACTLY.
WHEN WORKING WITH LEAD-ACID BATTERIES:
•Follow the recommended PPE requirements per the SDS for the battery to be used.
•If battery acid enters your eye, immediately flush your eye with running cold water for at least 15
minutes. Get medical attention immediately.
•If battery acid contacts skin or clothing, wash immediately with soap and water.
ALERT! Performing maintenance and/or troubleshooting procedures may interrupt power to the loads,
if battery reserve is not sufficient.
Personal Protective Equipment (PPE)
DANGER! ARC FLASH AND SHOCK HAZARD.
Appropriate PPE and tools required when working on this equipment. An appropriate flash protection
boundary analysis should be done determine the “hazard/risk” category, and to select proper PPE.
This product is intended only for installation in a Restricted Access Location.
Only authorized and properly trained personnel should be allowed to install, inspect, operate, or maintain
the equipment.
Do not work on LIVE parts. If required to work or operate live parts, obtain appropriate Energized Work
Permits as required by the local authority, per NFPA 70E “Standard for Electrical Safety in the
Workplace”.
Hazardous Voltage
DANGER! HAZARD OF ELECTRICAL SHOCK.
More than one disconnect may be required to de-energize the system before servicing.
Handling Equipment Containing Static Sensitive Components
ALERT! Installation or removal of equipment containing static sensitive components requires careful
handling. Before handling any equipment containing static sensitive components, read and follow the
instructions contained on the Static Warning Page.
Maintenance and Replacement Procedures
CAUTION! When performing any step in procedures that requires removal or installation of hardware,
use caution to ensure no hardware is dropped and left inside the unit; otherwise service interruption or
equipment damage may occur.
NOTE! When performing any step in procedures that requires removal of existing hardware, retain all
hardware for use in subsequent steps, unless otherwise directed.

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STATIC WARNING
This equipment contains static sensitive components. The warnings listed below must be observed to
prevent damage to these components. Disregarding any of these warnings may result in personal injury
or damage to the equipment.
1. Strictly adhere to the procedures provided in this document.
2. Before touching any equipment containing static sensitive components, discharge all static
electricity from yourself by wearing a wrist strap grounded through a one megohm resistor. Some
wrist straps have a built-in one megohm resistor; no external resistor is necessary. Read and follow
wrist strap manufacturer’s instructions outlining use of a specific wrist strap.
3. Do not touch traces or components on equipment containing static sensitive components. Handle
equipment containing static sensitive components only by the edges that do not have connector
pads.
4. After removing equipment containing static sensitive components, place the equipment only on
conductive or anti-static material such as conductive foam, conductive plastic, or aluminum foil. Do
not use ordinary Styrofoam™or ordinary plastic.
5. Store and ship equipment containing static sensitive components only in static shielding containers.
6. If necessary to repair equipment containing static sensitive components, wear an appropriately
grounded wrist strap, work on a conductive surface, use a grounded soldering iron, and use
grounded test equipment.

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CUSTOMER DOCUMENTATION PACKAGE
This document (UM582137200) provides User Instructions for the NetSure™ 5100 Series -48 VDC Power
System: Model 5100, Spec. No. 582137200.
The complete Customer Documentation Package consists of…
NetSure™-48 VDC Power System Installation Manual
•Power System Installation Instructions: IM582137200
NetSure™-48 VDC Power System User Manual
•Power System User Instructions: UM582137200
NetSure™NCU Controller User Manual
•NCU Controller User Instructions: UM1M830BNA
USB Drive with All Customer Documentation
•Power System Installation Instructions: IM582137200
•Power System User Instructions: UM582137200
•Power System “System Application Guide”: SAG582137200
•NCU Controller User Instructions: UM1M830BNA
•Rectifier Instructions: UM1R482000e3
•Engineering Drawings
-SD582137200
-T582137200
•Also provided on the USB drive is a controller configuration drawing and the controller configuration
files loaded into the controller as shipped.
SYSTEM DESCRIPTION
-48 VDC @ up to 150 Amperes Power System
The NetSure™ 5100 DC Power System is an integrated power system containing rectifiers, intelligent control,
metering, monitoring, and distribution.
This power system is designed to power a load while charging a positive grounded battery. This power system
is capable of operating in a batteryless installation or off battery for maintenance purposes. The power system
is designed for operation with the positive output grounded.
The NetSure 5100 consists of the following components mounted in a 19” or 23” wide relay rack or cabinet rack.
Wall mounting options are also available.
Controller
NCU (NetSure Control Unit): The controller provides power system control (including optional low voltage
battery disconnect [LVBD] and low voltage load disconnect [LVLD] control), rectifier control (including a
charge control function), metering functions, monitoring functions, local/remote alarm functions, and

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connections for binary inputs and programmable relay outputs via a controller interface board. The controller
also supports rectifier temperature compensation if the system is equipped with a temperature probe(s).
Temperature probe(s) may also be designated to monitor ambient temperature and/or battery temperature.
The controller also provides data acquisition, system alarm management, and advanced battery and energy
management. The controller contains a color TFT display and keypad for local access. The controller provides
an Ethernet port and comes with comprehensive webpages for remote access. The controller has optional
SNMP v3 capability for remote system management. The controller supports software upgrade via its USB port.
Refer to the NCU Controller Instructions (UM1M830BNA) for more information.
Rectifier Modules
The system contains rectifier modules, which provide load power, battery float current, and battery recharge
current during normal operating conditions. Refer to the Rectifier Instructions (UM1R482000e3) for more
information.
Distribution Unit
Various distribution unit options are available. See SAG582137200 for descriptions. The distribution unit can
be equipped with an optional Low Voltage Battery Disconnect (LVBD) or Low Voltage Load Disconnect (LVLD)
contactor. The distribution unit provides DC distribution through circuit breakers and/or fuses.
OPERATING PROCEDURES
Controller and Rectifier
For operation instructions on these units, refer to the following documents.
•NCU Controller Instructions (UM1M830BNA)
NOTE! The controller’s default “User Name” is "admin" and the default “Password” is “640275”.
•Rectifier Instructions (UM1R482000e3)
ESTOP Function
If an ESTOP switch is wired to the IB2-1 Controller Interface Board, customer-furnished system ground applied
to terminal DI8+ activates the ESTOP function. The ESTOP function shuts down and locks out the rectifiers
and opens the optional low voltage disconnect (LVD) contactors (battery and load type). If the system has
battery connected and does not contain a battery LVD or the controller power option is set to Battery Pwr
(jumper J4 on the system interface board is set to Battery Pwr), the controller will remain operational. If the
system does not contain battery or load LVD(s) and has battery connected, the loads will be sustained by the
battery voltage.
For Systems NOT Containing a Battery LVD: When the ESTOP signal is removed, LVD contactors (battery and
load type) will close after the “LVD Reconnect Delay” has elapse (customer configurable via the controller) if
battery voltage is present on the bus. Rectifiers will remain off. The rectifiers will restart when the input power
is removed and restored after 30 seconds or more (until the LEDs on the modules extinguish).
For Systems Containing a Battery LVD: When the ESTOP signal is removed, LVD contactors (battery and load
type) will remain open. Rectifiers will remain off. The rectifiers will restart when the input power is removed and
restored after 30 seconds or more (until the LEDs on the modules extinguish). When the rectifiers restart, LVD
contactors (battery and load type) will close after the “LVD Reconnect Delay” has elapse (customer
configurable via the controller).

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NOTE! If a customer-furnished method to disconnect the input power to the system is not provided, the
rectifiers will stay locked OFF until the input power is recycled. If the ESTOP signal is removed without
recycling the input power, the rectifiers will remain off and have a local alarm visible on the module. The
ESTOP alarm from the controller will extinguish. The controller will not issue an alarm for this condition.
Controller Battery Charge Current Limit Feature
Functionality: After a failure of the input source (commercial AC) or when some battery cells are permanently
damaged, the current to the batteries can be quite extensive. To avoid overheating or further damages to the
battery, the controller can be programmed to limit the battery current to a preset level by limiting the charging
voltage of the rectifiers. Should the battery current still exceed a higher preset value, an alarm is issued.
The controller limits the current going to the batteries based on the “Battery Current Limit” set point which is a
percentage of the battery capacity in C10. For example, 0.1C10 would mean 10% of the battery capacity.
Refer to the NCU Controller Instructions (UM1M830BNA) to program this feature. Battery charge current is
limited to the value set in the controller, as long as battery voltage is above 47 VDC.
Local Controls and Indicators
Controller and Rectifier
Refer to the controller and rectifier instructions for descriptions of the local controls and indicators located on
these units.
MAINTENANCE
System Maintenance Procedures
It is recommended to perform the maintenance procedures listed in Table 1every 6 months to ensure continual
system operation.
Table 1: Maintenance Procedures to be Performed at 6-Month Intervals
Procedure Referenced In
Check ventilation openings for obstructions
such as dust, papers, manuals, etc. --
Inspect and tighten all installer's
connections. IM582137200
Adding a Rectifier
To increase system current capacity, a rectifier module can easily be added if an empty rectifier module
mounting position is available.
Refer to Rectifier Instructions UM1R482000e3 for a rectifier installation procedure.

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Installing a Field Expansion Rectifier Shelf
DANGER! Adhere to the “Important Safety Instructions” presented at the front of this document.
NOTE! Refer to Figure 1 and Figure 2 as this procedure is performed.
Procedure
1. Remove the rear shield from the main module mounting assembly. This shield will not be re-used.
2. When the main module mounting assembly is configured with the front AC option, replace the mounting
angle on the left side (as viewed from the front) of the expansion module mounting assembly with the
longer mounting angle shipped loose with the expansion module mounting assembly.
3. Install the expansion module mounting assembly directly below the main module mounting assembly.
Use the mounting hardware provided with the expansion module mounting assembly. See Figure 1.
Refer also to Figure 1for hardware build-up and recommended torque.
NOTE! Install (orient) the ground washers so the teeth dig into the mounting angles for a secure
ground connection.
NOTE! Compliance with Telcordia GR-1089-CORE requires that prior to mounting the system to the
equipment rack:
•All paint must be removed from the front surface of each equipment rack rail where it mates with a
shelf-mounting bracket, so that good metal-to-metal contact can be established between the shelf
and rack.
•The shelf-to-rack mating surfaces must be cleaned.
•Electrical anti-oxidizing compound must be applied to the shelf-to-rack mating surfaces.
4. Remove the rear shield from the expansion module mounting assembly.
NOTE! Apply electrical anti-oxidizing compound to busbar mating surfaces before performing the next
step.
5. Remove the hardware from the main module mounting assembly’s -48V and return busbars.
6. Loosen the hardware from the expansion module mounting assembly’s -48V and return busbars.
7. Slide the busbars provided with the expansion module mounting assembly into position. These busbars
are installed between the busbar studs on the expansion module mounting assembly and the busbar
studs on the main module mounting assembly. Secure these busbars to the expansion module
mounting assembly with the hardware provided with the expansion module mounting assembly. Secure
these busbars to the main module mounting assembly with the hardware provided with the main module
mounting assembly. Refer to Figure 1for hardware build-up and torque.
8. Disconnect the cable coming from the distribution unit that is connected to the left side (as viewed from
the rear) connector on the main module mounting assembly. Connect this cable to the left side (as
viewed from the rear) connector on the expansion module mounting assembly. See Figure 2.

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9. Connect the cable provided with the expansion module mounting assembly between the left side (as
viewed from the rear) connector on the main module mounting assembly and the right side (as viewed
from the rear) connector on the expansion module mounting assembly. See Figure 2.
10. Install the new rear shields supplied with the expansion module mounting assembly to the rear of the
main module mounting assembly. See Figure 1.
11. Re-install the busbar shield previously removed from the expansion module mounting assembly. See
Figure 1.
12. Refer to the Power System Installation Instructions (IM582137200) and connect input power to the
expansion module mounting assembly.
13. Refer to the Power System Installation Instructions (IM582137200) and install rectifier modules into the
expansion module mounting assembly as required.

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Figure 1: Installing a Field Expansion Rectifier Shelf (cont’d on next page)
1. Remove rear shield from the
main module mounting assembly.
This shield will not be reused.
3. Install the expansion module
mounting assembly into the rack.
4. Remove rear shield from the
expansion module mounting assembly.
MOUNTING HARDWARE
12-24 x 3/4" Thread Forming
Hex Head Screw
No. 10/12 Ground Washer
Torque: 65 in-lbs.
Install the ground washers so the
teeth make contact with the metal
on the mounting angles.
23” Front AC Option Shown.
19” Rear AC Option Similar.
Rear
Shield
Rear
Shield
Rear
Rear
Front
2. When the main module mounting
assembly is configured with the
front AC option, replace the mounting
angle on the left side of the expansion
module mounting assembly with the
longer mounting angle shipped loose
with the expansion module mounting
assembly.

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Figure 1: Installing a Field Expansion Rectifier Shelf (cont’d from previous page, cont’d on next page)
Busbars slid into position.
Rear
Installed View
Hardware Build-Up:
Busbar
M6 Flat Washer
M6 Lock Washer
M6 Hex Nut
Torque to 52 in-lbs.
Hardware Build-Up:
Busbar
M6 Flat Washer
M6 Lock Washer
M6 Hex Nut
Torque to 52 in-lbs.
5. Install the busbarsprovided
with the expansion module
mountingassemblybetween the
shelves. Torque to52 in-lbs.
Dothis by removing the hardware from
the main shelf busbars, loosening the
hardwareon theexpansion shelf busbars,
andsliding thebusbars into position.
Apply electricalanti-oxidizing
compound to busbar mating surfaces.
Rear
Busbars

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Figure 1: Installing a Field Expansion Rectifier Shelf (cont’d from previous page)
Rear
Installed View
6. Install the new rear shields supplied
with the expansion module mounting
assembly to the main module
mounting assembly.
7. Re-install the rear shield (previously
removed) onto the expansion module
mounting assembly.
Rear

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Figure 2: Installing a Field Expansion Rectifier Shelf - Controller CAN Bus
Components removed in
illustration for clarity only.
Distribution Unit
List 01 Main Shelf
Distribution Unit
List 01 Main Shelf
List 02 Expansion Shelf
Cable P/N 555716
Provided with
Expansion Shelf
(Field Installed)
Exploded View Shown to
Illustrate Wire Connections Only
Termination Resistor
P/N 548398
Termination
Resistor P/N
RPM628350/2
Distribution Unit
with List 01
Distribution Unit
with List 01 and 02
Termination Resistor
P/N 548398
These Are Factory
Connected Together These Are Factory
Connected Together
These Are Factory
Connected Together
Connect
These
Together
DISCONNECT
These
Connectors
Termination
Resistor P/N
RPM628350/2

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TROUBLESHOOTING AND REPAIR
Contact Information
Refer to Section 4154 (provided with your customer documentation) for support contact information.
Controller and Rectifier
For troubleshooting and repair instructions on these units, refer to the following documents.
•NCU Controller Instructions (UM1M830BNA)
•Rectifier Instructions (UM1R482000e3)
Controller Configuration
If any controller configuration settings were changed, refer to the NCU Controller Instructions (UM1M830BNA)
and save a copy of the configuration file. This file can be used to restore the controller settings, if required, at a
later date.
NOTE! Provided on a USB drive furnished with the system is a Controller Configuration Drawing (C
drawing) and the controller configuration files loaded into the controller as shipped.
System Troubleshooting Information
This system is designed for ease in troubleshooting and repair. The various indicators as described in “Local
Controls and Indicators” on page 11 and in the controller and rectifier instructions are designed to isolate failure
to a specific element. Once the faulty element has been identified, refer to “Replacement Information” on page
19 and “Replacement Procedures” on page 19.
Troubleshooting Alarm Conditions on the Controller
The controller displays alarm conditions as listed in the “Resolving Alarms” section of the controller’s User
Manual. Programmable external alarm relays are also available. Refer to the System Installation Instructions
(IM582137200) and the Controller Configuration Drawing (C-drawing) supplied with your power system
documentation for your alarm relay configurations.
The controller’s Active Alarm and Alarm History submenus allow the User to view alarm details. Refer to the
NCU Controller Instructions (UM1M830BNA) to access these menus.
Checking the Controller’s Current Limit Point after Adding or Removing a Rectifier
If a rectifier module is added; the respective current limit point in amps will automatically increase to maintain
the same percentage. For example, if the current limit was set to 100% of combined capacity and a rectifier
module is added, the new current limit setpoint will be 100% of the combined capacity including the new
rectifier module.
If a rectifier module is removed from the system (and the Rect Comm Fail is cleared), the current limit point will
remain unchanged unless the capacity of the remaining rectifiers is not sufficient to maintain this current limit
point. If that happens, the current limit point will automatically decrease to the maximum (121% of the
remaining rectifiers).
It is recommended that the current limit point be checked whenever a rectifier is added to or removed from the
power system.

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When setting total rectifier current limit, the set point to each rectifier is the total set point divided by the
number of rectifiers. For example, if the system contains five rectifiers and the current limit is set to 150 amps
then each rectifier has a current limit set point of 30 amps. If one or more rectifiers are removed or fails it will
take several seconds for the individual set points to the remaining rectifiers to be reset. In the example given, if
one rectifier is removed the current limit set point will drop to 120 amps (30 amps times four remaining
rectifiers) until the controller can send updated set points to the remaining rectifiers. This takes a couple
communication cycles (several seconds) after which each rectifier would have a new set point of 37.5 amps for
a total of 150 amps. The total current limit of the rectifiers should not be set such that the loss of the
redundant rectifiers will cause this temporary set point to drop below the actual maximum expected load. If
batteries are used on the rectifier output, the batteries should support the load until the current limit set points
can be re-established due to loss of a rectifier.
Refer to the NCU Controller Instructions (UM1M830BNA) for a procedure.
Clearing a Rectifier Communications Fail Alarm after Removing a Rectifier
If a rectifier module is removed from the system, a rectifier communications failure alarm is generated. If the
rectifier module will not be replaced, the alarm should be cleared.
Refer to the NCU Controller Instructions (UM1M830BNA) for a procedure.
Clearing a Rectifier Lost Alarm
If the controller resets while a rectifier communications fail alarm is active, the rectifier communications fail
alarm is replaced with a rectifier lost alarm.
Refer to the NCU Controller Instructions (UM1M830BNA) for a procedure to clear the alarm.
Replacement Information
Replacement Assemblies
When a trouble symptom is localized to a faulty rectifier, controller, or system circuit card; that particular device
or circuit card should be replaced in its entirety. No attempt should be made to troubleshoot or repair
individual components on any rectifier, controller, or circuit card.
Refer to System Application Guide SAG582137200 for replacement part numbers.
Replacement Procedures
DANGER! Adhere to the “Important Safety Instructions” presented at the front of this document.
Replacing a Rectifier
Refer to the Rectifier Instructions (UM1R482000e3) for a rectifier replacement procedure. Refer also to
“System Troubleshooting Information” on page 18.
The rectifier being replaced is assigned by the NCU the lowest available identification number. If desired, you
can change the identification number, see “Configuring the NCU Identification of Rectifiers” in the separate
Power System Installation Manual (IM582137200).
Replacing the NCU Controller
Refer to the NCU Controller Instructions (UM1M830BNA) for a controller replacement procedure.

Vertiv |NetSure™ 5100 Series -48 VDC Power System User Manual (UM582137200)|Rev. G
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Replacing a Distribution Device
Replace distribution devices with the same type and rating. Refer to System Application Guide SAG582137200
for part numbers.
Replacing a GMT Distribution Fuse
Procedure
1. Refer to Figure 3and replace the fuse. Ensure a safety fuse cover is installed on the replacement fuse,
as shown in Figure 4.
2. Verify no alarms are active.
Replacing a Bullet Nose Circuit Breaker
Procedure
1. Operate the defective circuit breaker to the OFF position.
2. Gently rock the defective circuit breaker back and forth while pulling firmly outward until the breaker is
free from the distribution unit.
3. Ensure that the replacement circuit breaker is in the OFF position, and is of the correct rating.
4. Orient the replacement circuit breaker as shown in Figure 5or Figure 6. Insert the terminals on the rear
of the circuit breaker into their corresponding sockets on the distribution unit. Ensure the alarm contact
on the back of the circuit breaker makes contact with the alarm terminal on the distribution unit. Push
distribution device in firmly until fully seated in the distribution unit.
5. Operate the replacement circuit breaker to the ON position.
6. Verify no alarms are active.
Figure 3: GMT Distribution Fuse Replacement (List BA, BC, BF, LC, NA, NC, NF)
GMT Fuse
Safety Cover
Front
List BA shown,
List BC, BF, LC, NA, NC, NF similar.