ABB OVR-15 Operation and maintenance manual

—
DISTRIBUTION SOLUTIONS
OVR-15, 27 & 38 Outdoor Vacuum Recloser
Low Voltage Unit
Instruction, operation, and maintenance manual

2 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
Copy Right
This manual and parts thereof must not be reproduced or copied without written permission from
ABB, and the contents thereof must not be imparted to a third party, nor used for any unauthorized
purpose.
Disclaimer
The data, examples and diagrams in this manual are included solely for the concept or product
description and are not to be deemed as a statement of guaranteed properties. All persons
responsible for using the equipment addressed in this manual must satisfy themselves that each
intended application is suitable and acceptable, including that any applicable safety or other
operational requirements are compiled with. In particular, any risk in applications where a system
failure and/or product failure would create a risk for harm to property or persons (including but not
limited to personal injuries or death) shall be the sole responsibility of the person or entity applying
the equipment and those so responsible are hereby requested to ensure that all measures are taken
to exclude or mitigate such risks.
This product has been designed to be connected to medium voltage distribution networks. It is the
sole responsibility of the person or entity responsible for the network administration to ensure a
secure connection to the network and take necessary measures to protect the product and the
network, its system and interface included against any kind of security breaches, unauthorized
access, interference, intrusion, leakage and /or thefts. ABB is not liable for any such damages and/or
losses.
This product is intended to be operated and maintained by qualified personnel, thoroughly trained
and knowledgeable with regards to the associated hazards involved. This publication is written only
for such qualified personnel and is not intended to be a substitute for adequate training and
experience in the safety procedures for this device.
This document has been carefully checked by ABB, but deviations cannot be completely ruled out. In
case any errors are detected, the reader is kindly requested to notify the manufacturer. Other than
under explicit contractual commitments, in no event shall ABB be responsible or liable for any loss or
damage resulting from the use if this manual or the application of the equipment.

3 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
1CONTENTS
A. Introduction..........................................................................................................................................6
B. Environmental protection program ................................................................................................6
C. End of life recycle/disposal...............................................................................................................6
D. Product related safety notices......................................................................................................... 7
E. Working on LV cabinets and mandatory safety procedures. ....................................................8
F. Warning Texts and Symbols..............................................................................................................9
2Packing and transport......................................................................................................................10
3Receipt and Storage prior to installation .....................................................................................11
4General Description of LV cabinet of OVR-15, 27 & 38 recloser .............................................. 14
4.2.1 Low voltage control cabinet (LV cabinet) ............................................................................................................ 14
4.2.2 Intelligent battery charger: ..................................................................................................................................... 15
4.2.3 Auxiliary supply .......................................................................................................................................................... 15
4.2.4 Actuator Control Module ......................................................................................................................................... 15
4.2.5 Rechargeable Batteries............................................................................................................................................ 16
4.2.6 SERVICE and DISCHARGE modes........................................................................................................................... 17
4.2.7 External Auxiliary Supply Status monitoring....................................................................................................... 17
4.2.8 RER615 control ........................................................................................................................................................... 17
5Standard production tests..............................................................................................................19
6Installation .......................................................................................................................................... 19
7Inspection and maintenance ..........................................................................................................25
8Common troubles and trouble shooting ..................................................................................... 27
9General OVR-15, 27 & 38 Block Diagram .......................................................................................29

4 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
10 Typical rating plate details.............................................................................................................. 31
11 General Arrangement drawings .....................................................................................................32
12 Parameters to be maintained as default in RER615..................................................................33
13 RER615 Settings.................................................................................................................................36
14 Annexure I : Typical functional characteristics of sealed lead acid batteries .....................43

5 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
For your safety!
- Make sure that the installation place & environment is suitable for the electrical
apparatus.
- Check that all the installation, putting into service and maintenance operations
are carried out by qualified personnel having relevant knowledge of the
apparatus.
- Make sure that the standard and legal prescriptions are complied with during
installation, putting into service and maintenance, so that installations
according to the rules of good working practice and safety in the workplace are
constructed.
- Strictly follow the information given in this instruction manual.
- Ensure that the rated performance of the apparatus is not exceeded during
service.
- Ensure that the personnel operating the apparatus have this instruction
manual to hand as well as the necessary information for correct intervention.

6 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
A. INTRODUCTION
This manual contains the information needed to install Low voltage (LV) cabinet of medium voltage
OVR-15, 27 & 38 vacuum recloser and put them into service.
For correct use of the product, please read this manual carefully along with instruction, operation, and
maintenance manual for high voltage unit.
OVR-15, 27 & 38 reclosers are designed for different installation configurations. However, the mounting
structure for this apparatus allows further technical-construction modifications (at the customer’s
request) to adapt to special installation requirements. Consequently, the information given below may
sometimes not contain instructions concerning special configurations.
Apart from this manual, it is therefore always necessary to consult the latest technical documentation
(electric circuit and wiring diagrams, assembly and installation drawings, any protection coordination
studies, etc.), especially regarding any variants requested in relation to the standardized configurations.
Only use original spare parts for maintenance operations. For further information, please refer
recommended spare part list mentioned in this manual.
All the installation, putting into service, running and maintenance operations must be carried out by
skilled personnel with in-depth knowledge of the apparatus.
B. ENVIRONMENTAL PROTECTION PROGRAM
OVR-15, 27 & 38 reclosers LV cabinet recloser is manufactured in accordance with the ISO 14001
Standards (Guidelines for environmental management).
The production processes are carried out in compliance with the Standards for environmental protection
in terms of reduction in energy consumption as well as in raw materials and production of waste
materials. All this is thanks to the medium voltage apparatus manufacturing facility environmental
management system.
C. END OF LIFE RECYCLE/DISPOSAL
ABB is committed for complying with relevant legal and other statutory requirements for environment
protection according to the ISO 14001 standard. The duty of the end user is to facilitate end of life
recycling & disposal according to the applicable regulations.
During disposal of product, it is necessary to act in according with local legal requirements in force.
Disposal can either be carried out thermally in an incineration plant or by storing on a waste site.
Following are the methods of recycle/disposal:

7 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
Table 1 : Recycle/disposal methods
Raw Material
Recycle
Environmental effects & reuse processes
Iron
Yes
Separate, utilize in favor of new source (ore)
Stainless steel
Yes
Separate, utilize in favor of new source (ore)
Copper
Yes
Separate, utilize in favor of new source (ore)
Brass
Yes
Separate, utilize in favor of new source (ore)
Aluminum
Yes
Separate, utilize in favor of new source (ore)
Zinc
Yes
Separate, utilize in favor of new source (ore)
Thermoplastic
Yes
Make granulate, re-use or apply as energy superior
Rubber
Yes
Cut into pieces & use as high-grade energy
Packing foil
Yes
Cut into pieces & used for landfills
Wooden pallet
Yes
High grade energy additive in refuse incineration
D. PRODUCT RELATED SAFETY NOTICES
The OVR-15, 27 & 38® recloser LV cabinet should be installed within the design limitations as described on
its nameplate and in these instructions. In addition, always follow your company’s safety procedures.
For the safety of the personnel performing maintenance operations on the recloser or connecting
equipment, all components should be electrically disconnected by means of a visible break and securely
grounded.
This manual uses terms “ground” & “grounding” as per IEEE. These are equivalent to IEC terms”
earth” and “earthing”.
This manual contains terms and expressions commonly used to describe this kind of equipment.
These instructions do not attempt to provide the user of this equipment every possible answer to
questions which may appear in the application, operation, and maintenance of the product.
Detailed descriptions of standard repair procedures, safety principles, and service operations are not
included. It is important to note that this document contains some warnings and cautions against some
specific service methods that could cause personal injury to service personnel or could damage
equipment or render it unsafe. These warnings do not cover every conceivable method in which service
(whether or not recommended by ABB) may be performed.
Secondly, ABB cannot predict or investigate all potential hazards resulting from all conceivable service
methods. Anyone using service procedures or tools, whether or not recommended by ABB, must be
completely certain that both their personal safety and the safety of the equipment will not be jeopardized
by the service method or tools selected.
All information contained in this manual is based on the latest product information available at the time
of printing. The right is reserved to make changes at any time without notice.

8 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
Also, as improvements in assemblies and parts are made, some parts may differ in appearance that
depicted in illustrations; however, functionality will be equivalent.
E. WORKING ON LV CABINETS AND MANDATORY SAFETY
PROCEDURES.
Whenever it is required to work on LV Cabinet, it is mandatory to follow following minimum procedures:
a. Isolate the recloser from power system on its both sides. Put recloser in OPEN condition by
operating the emergency manual trip handle (yellow handle).
b. Confirm the OPEN status of the recloser from the mechanical ON/OFF indicator, from SLD on LCD
display & the indication LEDs on RER615 HMI.
c. Always put the SERVICE /DISCHARGE selector switch in the LV cabinet to DISCHARGE position.
d. Follow the safety warning instructions on various warning labels provided on the LV & HV units
e. Remove the control cable from both HV & LV cabinets & cover the 24 pin male connectors by plastic
caps provided.
Although warning hazards are related to personal injury, it is necessary to understand that under certain
operational conditions, operation of damaged equipment may result in degraded process performance
leading to personal injury or death. Therefore, comply fully with all warning and caution notices.

9 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
Danger
Warning
Caution
Note
Important
F. WARNING TEXTS AND SYMBOLS
Warning texts mentioned are stated based on different degrees of urgency, which should be carefully
observed. These are described below.
Danger Indicates an immediate risk situation that can lead to
death or serious personnel injury if not avoided
Warning Indicates an immediate risk situation that can lead to
death or serious personnel injury if not avoided
Caution Indicates a risk situation that can lead to small or
moderate damage
Note is used when there is a danger that can lead to equipment
damage only.
Important indicates an operation or a suggestion for handling.
Warning Symbols
Following warning symbols may appear on warning sticker as a part of the product.

10 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
2PACKING AND TRANSPORT
GOODS MARKING
The factory assembled LV cabinet transported in different packing case and its mounting brackets. Each
case is marked with case markings on two sides with indelible black ink. The case markings include
information of case number, gross weight, etc.
In addition to the above, the cases are marked with the following symbols. These should be observed
when choosing lifting equipment.
Figure-1 : General symbols on packing case
DOCUMENTS
Documents provided with the LV unit during dispatch.
- Instruction manual
- Operator’s quick reference guide
- Routine test certificate
- Drawings
- Packing list
- Other documents as mutually agreed in contract with ABB
TRANSPORT AND LIFTING
The LV cabinet shall be transported in packed condition only. Before lifting the case, observe the
information on it (such as symbol, weight, etc.).
Following precautions are to be taken while lifting:
- Ensure that packing cases are not placed on wet surfaces / waterlogged areas.

11 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
- LV cabinet should not be stacked one over the other.
- LV cabinet should be lifted by a lifting device equipped with forks or slings. If a crane is used, slings
shall be used. The units must not be rolled or dropped.
Figure-2 : Packing case lifting arrangement
3RECEIPT AND STORAGE PRIOR TO INSTALLATION
RECEIPT OF RECLOSER
Each LV cabinet is assembled and tested at the factory. Prior to shipment, the equipment is thoroughly
inspected to ensure a quality product free from defects. If damage is noticed, call the carrier at once for
inspection, and request an inspection report. Afterwards, file a formal claim with the carrier, supported
with the Airway/Roadway Bill.
Each delivery, on receipt, should be checked for,
- Shortages and discrepancies. (Check against order and delivery documents).
- Any transit damage and material losses.
- Abnormality, if any, must be notified immediately to ABB, forwarding agents and the insurance
company.
Instructions and literature packed with the LV unit should be kept with the unit. Additional copies may
be obtained upon request from the local ABB sales office. Following are the typical parts in which
recloser are generally shipped from factory.

12 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
Default Shipment
Low Voltage (LV) control cabinet
Optional items
(only if ordered separately)
Mounting brackets
Auxiliary power cable (2x1.5 sq.mm)
Any additional spares
STORAGE OF RECLOSER LV UNIT
The LV Cabinet with complete packing should always be stored indoor to protect from direct sunlight &
rain or snow. The LV cabinet should be stored in its original transport units, where they are well
protected from damage.
LV cabinet can be stored up to 3 months from date of shipment from the factory. For longer storage, the
packing needs to be removed and the recloser to be kept under controlled environmental conditions.
We define storage in controlled conditions as a place with:
- Leak proof roof
- Solid, flat ground
- Relative humidity less than 50%
- Temperature 20 0C (+10oC)
- The heating elements must be connected to the electric supply to protect the control equipment
from corrosion or freezing damage.
The LV cabinets must be stored in the upright position to avoid moisture accumulation.
Recommended storage temperature range is -20 Deg C to + 40 Deg C.
The LV control cabinet has rechargeable batteries inside. A periodic check of battery
voltage (24V) & periodic charging of the batteries (typically every three months) may be
required in case of prolonged storage. For the batteries in your control cabinet, refer to
technical documentation of the respective battery manufacturer. Also refer the section
“Inspection & Maintenance” for further information.
If the LV cabinet is not placed in service immediately, it is essential that proper care be
exercised in handling and storage to ensure good operating condition in the future.
Please consult ABB if the recloser will be in storage for an extended period of time
before installation.
Important
Note

13 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
Caution
Caution
Caution
HANDLING
The LV cabinet come with welded lifting brackets on the sides of these cabinets for lifting. A four-point
lift is strongly recommended using the loops in these brackets. The approximate mass in Kg is
separately mentioned on rating plates on HV & LV cabinets.
Figure-3 : LV Cabinet lifting detail
Exercise care during lifting to avoid damage to the poles
Do not place the recloser LV unit on an uneven surface. Placing the LV unit on an uneven
surface may cause tilting / galling of the HV unit causing damage to the equipment and
injuries to the person nearby
Exercise care during lifting to avoid damage to the poles

14 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
4GENERAL DESCRIPTION OF LV CABINET OF OVR-15, 27 &38
RECLOSER
LV CABINET ASSEMBLY
Each LV cabinet of OVR-15, 27 & 38 Recloser has intelligent battery charger, capacitors, control modules,
relay and battery with their hard-wired circuits. Please refer the LV GA for the other constructional
details.
CONTROL
4.2.1 Low voltage control cabinet (LV cabinet)
A weatherproof, IP55 rated cabinet, houses the low voltage control components. The LV cabinet has an
outer hinged swing door with padlocking provision. The control and protection relay RER615, is mounted
on an inner hinged swing door to allow front and rear access to it. All the MCBs, service/discharge switch
and auxiliary power socket for laptop charging are mounted on the front side of inner swing door for
easy access to operator. Other devices including space for mounting optional radio modem is provided
on the side/rear walls of the cabinet.
The floor of the LV cabinet is equipped with removable gland plate to provide entry to auxiliary power
cable, communication cables, 50W thermostatically controlled heater is provided to prevent
condensation in the LV cabinet.
Figure-7: LV control cabinet overview

15 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
4.2.2 Intelligent battery charger:
The Intelligent battery charger indicated here is to convert the auxiliary power supply from connected
from External PT or equivalent to suitable form required by components like Battery, RER615, ACM and
external communication modem. This Battery charger is temperature compensated.
4.2.3 Auxiliary supply
The LV control cabinet requires auxiliary power to operate the Recloser, Actuator control Module (ACM),
HV & LV cubicle heating, illumination, etc. A separate outdoor type 2 x1.5 Sq.mm jacketed cable is
required to connect the external auxiliary power to the LV cabinet. Pl refer the Recloser quick reference
guide for details.
For the auxiliary supply voltage / frequency applicable for your recloser, please refer the approved / as
built drawings.
MCB is provided inside the cubicle for protection of Intelligent Battery charger, cubicle heating,
illumination, and auxiliary power socket outlet.
The auxiliary power outlet on the inner swing door is only meant for laptop charging in
emergency situations. It should not be used for any other means as it may burden the
external auxiliary power source .
4.2.4 Actuator Control Module
The Actuator Control Module (ACM) module gets its power supply from
Intelligent battery charger.
ACM regulates the closing and tripping signals to magnetic actuator as per the
feedback from HV unit and interaction with relay by charging/discharging the
capacitors.
ACM is hardwired to RER615 relay to perform operations.
Figure-8: Actuator Control Module
Note

16 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
4.2.5 Rechargeable Batteries
The LV unit is supplied with two 12 V batteries connected in series and securely mounted in the LV
cabinet for providing back up power to recloser in case of external auxiliary power failure. The batteries
are protected by separate MCB.
Typically, the battery bank ensures minimal stand-by back up for 24 hours at 20 °C from a fully charged
initial condition. However, the actual backup duration depends upon various site conditions such as:
- Ambient temperature & initial condition of the battery (temperature & storage period before
commissioning, periodic charge/discharge, battery maintenance)
- Frequency of external auxiliary power outages & duration of each outage (i.e. the number of
charging/discharging cycles) and depth of each discharge.
- Percent charging (terminal voltage) of the battery at the time of outage of external auxiliary power.
For additional details it is recommended to refer battery manufacturer documentation. Please also refer
the section “Inspection & Maintenance” of this manual.
A battery temperature sensor is provided near the battery bank terminals. Battery Charging temperature
range is -20 + 50°C.
We are providing Valve Regulated Lead Acid (VRLA) batteries which are temperature & charging voltage
sensitive. Although maintenance by way of water topping up is not required, regular checking and
assurance of proper charging voltage, depth of discharge and operating temperature is needed.
In case of loss of external auxiliary supply, the intelligent battery charger switches over to battery bank
for power and continues to conduct its function. Recloser will work as long as the battery bank voltage
remains above 20.5V. Below 20.5 V load management algorithm activates within intelligent battery
charger and disconnects the power feed to ACM, RER615 and optional radio modem. This is done to
prolong the batteries going into deep discharge mode. With relay not being powered, the recloser will
not be able to perform any operation.
- Due to frequent and long duration external power outages, battery frequently undergoes
discharge and charge cycles. This reduces battery capacity, charging efficiency & overall
service life.
- During consistent long duration outage, the battery bank voltage may drop below 18V (9V
per battery) indicating battery might have deep discharged & now cannot be charged
again. At this point, the battery needs complete replacement by a brand new, fully charged
equivalent battery.
- Connection of any additional load to battery is strictly prohibited, and ABB will not be liable
for any adverse impact it can create to recloser performance including life of battery.
- Handling reclosers during long outages
1. If battery bank is healthy and in fully charge condition i.e. ≥ 24 Vdc, for the power outage
can be of < 24Hrs. without any special attention required.
2. If power outage is for more than 24 Hrs OR typically > 10 CO operations after power
failure, then it is considered as long power outage requiring special attention of
batteries.
3. During long outages, the batteries might get drained to such a level that it might go into
deep discharge stage i.e. battery bank voltage goes below 18 V.
4. In this situation recloser will not be able to recharge the batteries automatically and
external charging may be required. Such situation might also damage batteries
permanently and thus required to be replaced.
5. To avoid such situation, in case of power outage is expected to be more than 24 Hrs.
switch OFF the battery MCB in the beginning of the outage and when the power resumes,
switch it back to ON.
6. If power outage is more than a month, then charge the batteries on regular interval
externally to ensure the battery bank voltage is always more than 21 VDC.
Caution

17 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
4.2.6 SERVICE and DISCHARGE modes
A two position (Service & Discharge) selector switch is provided in the LV cabinet. For normal situations
when the recloser is in service, this switch should be in Service position. In case, any maintenance is to be
conducted inside the LV cabinet, the switch should be moved to Discharge position to ensure operator’s
safety from charged capacitors.
SERVICE Mode: For normal operation of recloser; the selector switch must be put in service mode. All the
MCBs are in ON condition and the capacitors are kept fully charged by the ACM.
DISCHARGE Mode: Since the LV cabinet houses charged capacitors, it is mandatory that the operator
should properly discharge them before conducting any maintenance inside the LV cabinet. For safely
discharging the capacitors, a capacitor discharge circuit is provided in the LV cabinet.
The operator has to put the selector switch into Discharge mode upon which, the capacitors get
connected to the discharge circuit. In Discharge mode, the capacitors are no more charged.
A red LED is provided on the discharge circuit to indicate the process of capacitor discharge. It takes few
minutes for the capacitors to get safely discharged. This red LED starts glowing as soon as the switch is
put in discharge mode and continues to glow until the capacitors are discharged to a safe level (around
2V).
Operator should wait until this red LED indication is turned OFF before touching any component inside
the LV cabinet. In discharge mode protection & control are not available for the recloser.
4.2.7 External Auxiliary Supply Status monitoring
In the event of loss of external auxiliary supply, the Intelligent battery Charger sends signal to RER615
relay over an independent binary input. Thus, the status of availability of external auxiliary power to the
LV unit can be monitored remotely in case communication set-up is made available.
4.2.8 RER615 control
OVR-15, 27 & 38 recloser LV cabinet is supplied with the microprocessor-based RER615 Intelligent
Electronic Device (IED) from ABB’s Relion family. This technologically advanced relay integrates all
traditional recloser control functions with new advanced functions, such as three phase inrush and
programming flexibility, providing a wide range of metering and remote control options.
For details on relay programming, operations, and testing, refer to technical documentation at
www.abb.com. For details on the overall control circuit, refer to the approved/as built wiring diagram
supplied with the recloser.
The RER615 implements a draw out case design for easy removal and internal upgrades. This design has
two main parts: the frame and the case. The frame is fixed on the inner swing door of the LV cabinet. The
case is removable via a handle and houses various cards. All card connections are made with terminal
blocks that are affixed to the frame of the IED. This is powered by the charging device.

18 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
Figure-9 : RER615 Display screen and LEDs on front facia
Figure-10 : RER615 Buttons / Keys on front facia
Figure-11 : RER615 Modules for OVR reclosers - configuration ‘D’

19 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
The RER615 is not intended for “hot swapping.” Read section 8.1 before removing
the relay from its case. When the RER615 is removed from its case, the current (I)
input terminals automatically short circuit the CT inputs. No card should be
removed from the RER615 in the fi eld. If removal is required, contact the ABB
Customer Service Group
The LV unit is shipped duly calibrated with the current /voltage correction factors (as
applicable) already applied and set in the RER615 relay. It is mandatory that these
correction factors are not modified after shipment.
RER615 Parameter Settings at the time of shipment from factory:
Other than the “Parameters to be maintained as default in RER615” listed in Section-
13 & the rated reclosing cycle in DARREC1 functional block, rest all parameter settings
in RER615 are the “default settings” as per RER615 technical manual on ABB website.
5STANDARD PRODUCTION TESTS
OVR-15, 27 & 38 recloser LV cabinet is tested thoroughly in factory before supplying. The standard
factory production tests include:
1. Verification of wiring as per approved wiring diagram.
2. Electrical operation:
a. Close and Open in Local/Remote modes
b. Overcurrent response and automatic reclosing through primary injection.
3. Functional checks of manual controls (K69) & associated electrical & mechanical close block
4. Minimum Trip and Time-Current Test
5. No load mechanical operation test.
A standard routine test report with a summary of results is shipped as a part of documentation package.
6INSTALLATION
The OVR-15, 27 & 38 recloser LV unit can be installed in a substation frame, pole-mounting frame, or can
be mounted into a customer supplied structure. However, it is required that in all of the mounting
methods the LV unit be vertical, levelled and securely fastened.
Before shipping from factory, the OVR-15, 27 & 38 recloser LV control cabinet are tested as a system in
factory. It is mandatory that during installation, the HV unit and LV control cabinet should be properly
matched by serial number mentioned on rating plates provided on each of them.
- All metal mounting frames and structures must be commonly grounded to the
grounding grid at site. For proper operation of the electronic components, it is
mandatory that the total impedance of the grounding grid at site should be less than
one Ohm (1 Ω)
- It is also mandatory to ensure that all the grounding connections to the welded star
grounding pad inside the LV cabinet are always intact and secured.
- Be careful not to bend the cable below a radius of 12 inches to avoid damage to itself.
Note
Important
Important
Note

20 | P a g e
OVR-15, 27 & 38 LV cabinet Instruction Manual
Important
GROUNDING
Always follow international, national and company specific regulations when
grounding the equipment.
All metal mounting frames and structures must be commonly grounded to the grounding grid at site.
Grounding is important to ensure proper operation of all electronic components, as well as to prevent
penetration of EMC noise and other transients into the sensitive electronic circuits (RER615 relay, ACM,
radios, etc.). Each LV cabinet includes two stainless steel welded grounding pads for grounding and M8
stud as shown in below figure. 80 Sq.mm cross-section, solid copper strip/equivalent is recommended
for grounding.
For the proper operation of electronic components, it is mandatory that the total impedance of
grounding grid at site should be less than one Ohm (1 Ω). It is also mandatory to ensure that all the
grounding connections to the welded star grounding pad inside the LV cabinet are always intact and
secured.
Figure -13: Provisions for Grounding Connections on LV cabinet
Grounding terminal(M8)