Eaton RVAC Technical manual

Instruction Leaflet IL0102002E
Ring Main Unit Operation Instruction
Effective April 2018
Product Type
RVAC
Product Name
Indoor, Fixed, AC Metal-Enclosed Switchgear (SF6 RMU)

2 EATON CORPORATION www.eaton.com
Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
Dear Customers:
Add optional mark.
Thank you for your purchase of the indoor fixed AC metal enclosed
switchgear (thereafter as SF6 RMU). For correct and safe
operation of this equipment, make sure to read this manual
carefully prior to the installation of the equipment. Please keep the
manual properly after reading, for future reference when
necessary.
The manual is aimed to assist technicians to install, commission,
operate, run and maintain SF6 ring main units (RMU). Users shall
observe proper operating procedures in running the equipment.
The manual has considered the issues as specific as possible
during the installation and usage, but can not cover all the possible
changes concerning the equipment itself and the operating
conditions. In case of any special occurrence, contact the After
Sales Department of Cooper Power System.
The information within the manual is subject to changes without
further notice.
WARNING
THIS IS A SIGN TO INDICATE THAT FAILURE TO FOLLOW THE
OPERATING INSTRUCTIONS MAY CAUSE PERSONAL INJURIES OR LIFE
DANGERS.
CAUTION
THIS IS A SIGN TO INDICATE THAT FAILURE TO FOLLOW THE
INSTRUCTIONS MAY CAUSE DAMAGES TO THE EQUIPMENT.

3EATON CORPORATION www.eaton.com
Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
Contents
Description Page
Chapter 1 Product introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. Catalogue numbering system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5. Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6. Typical functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7. Typical schemes and structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 2 Transport, handling, inspection and storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Transport and handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. Inspection and storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. RMU dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. Base form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. RMU fixation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. RMU grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5. Cable installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6. Fuse installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7. Cabinet connection and installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8. Inspection and cleaning after installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 4 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Load switch cabinet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. Combination unit cabinet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. Circuit breaker cabinet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. RVAC cabinet types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 5 Operation, maintenance and repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Notice for operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. Maintenance and repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 6 Supplied documents and accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 7 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
4 EATON CORPORATION www.eaton.com
1. General description
Chapter 1 Product introduction
The RVAC indoor fixed AC metal enclosed switchgear (hereafter
as RMU) is a new generation of SF6 gas insulated switchgear
developed by Cooper Power Systems, relying on the Edison R&D
center of powerful technical advantages, adopting the computer
simulation technology, aimed to provide high quality products for
electric network. This product is mainly used for the secondary
electrical distribution system of 3-phase AC 50Hz, with the rated
voltage of 12kV and 24kV, especially applicable for capturing and
distributing electric power in power systems such as small-sized
secondary distribution substations, switching stations, industrial
and mining enterprises, urban residential areas, airports, railways,
tunnels, and high rise buildings, greatly improving the reliability
and utilization rate of the power supply.
This product adopts a three-phase common enclosure structure,
using SF6 gas of excellent insulation and arc extinguishing
performance as medium, and achieving the goal of miniaturization
and light weight with optimized design; the product also uses
interface insulation structure, allowing flexible plug-in and
expansion of high voltage components. The product offers a range
of advantages such as simple structure, compact size, low price,
small floor space, high power supply quality and high power
supply safety. The basic module is a one-circuit load switch
cabinet and a one-circuit load switch plus current limiting fuse
combination cabinet module. In addition, several additional
modules are offered, including 3-circuit common enclosure RMU
(two incomings and one outgoing), one incoming and one
outgoing, bus tie cabinet, metering cabinet, voltage transforming
cabinet. The circuit breaker cabinet is also developed and
equipped, to expand the usage scope of the RMU. On the basis of
the indoor cases, the corresponding outdoor cases are supplied to
expand the use in outdoor environments.
The RUM has been equipped separately with primary circuit
devices inside the sealed enclosure, including the load switch or
load switch plus current limiting fuse. The load switch is used to
control the circuits to open and close load current and overload
current, while the load switch plus current limiting fuse is used to
control, open and close, and isolate the transformer and its
distribution circuit, as well as to offer protections against short
circuit current and overload current at the medium voltage side of
the medium voltage transformer, the transformer and low voltage
distribution circuits.
2. Operating conditions
2.1. Ambient air temperature:
Upper limit: +40°C, and the average temperature measured
within 24 hours ≤35°C;
Lower limit: -40°C;
2.2. Humidity
Relative humidity: daily average ≤95%,
monthly average ≤90%.
Vapor pressure: daily average ≤2.2kPa,
monthly average ≤1.8kPa.
2.3. Altitude: ≤1000m.
2.4. The ambient air is not apparently affected by dust, smoke,
corrosive or flammable gas, vapor or salt mist pollutions.
2.5. The vibration or quake external to the switchgear and
controlgear is negligible.
2.6. The amplitude of the electromagnetic interference induced in
the secondary system does not exceed 1.6kV.

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
5EATON CORPORATION www.eaton.com
3. Catalogue numbering system
The structure and meaning of the catalogue numbering system are shown below.
4.1. Rated technical data:
4. Technical data
RMU product code
Rated current (A) of the fuse
Rated short-time withstand current (kA)
of the load switch
Breaking current of the fuse
Voltage class (12kV/24kV)
Rated current (A) of the load switch
RVAC - □24 / 630 20- 80 - 31.5
K= load switch unit
T= combination unit
V= circuit breaker unit
S= bus coupling unit
B (A) = cable lifting unit
PT = voltage transforming unit
M= metering unit
No. Item Unit Data
1 Rated voltage kV 12*
2 Rated frequency Hz 50
3 Rated current Load break switch A
A
630
LBS+FUSE Combination unit 125
4 1min power frequency withstand voltage Phase to earth, phase to phase kV
kV
42
Isolating distance 48
5 Lighting impulse withstand voltage Phase to earth, phase to phase kV
kV
75
Isolating distance 85
6 Short-time withstand current (rms) Main circuit 4s kA
kA
20
20Earthing switch 2s
Earthing connection circuit 2s kA 17.4
7 Short-time withstand current (peak) Main circuit kA
kA
50
50Earthing switch
Earthing connection circuit kA 43.5
8 Rated short circuit making current (peak) Load break switch kA 50
kA 50
Earthing switch
9 Load break switch’s rated active load breaking current A630
10 Load break switch’s rated closed-loop breaking current A 630
11 Load break switch’s 5% rated active load breaking current A 31.5
12 Load break switch’s rated cable charging breaking current A 10
13 Fuse’s rated short circuit breaking current kA 31.5
14 Fuse’s rated short circuit making current kA 80
15 Load break switch’s rated transfer current A 1850
16 Load break switch’s rated active load breaking operations operation 200
17 Ground fault current switching A 5 (10 operations)
18 Line and cable charging current switching under the ground fault conditions A 20 (10 operations)
19 Mechanical Endurance Load break switch operation 5000
Earthing switch operation 2000
20 Rated pressure of SF6 gas (20°C, meter pressure) MPa 0.03
21
*12kV series of RVAC just verified and applied in China (with GB certifications). Any doubt please contact us.
SF6 gas leakage rate yearly ≤0.1%
Data
24
50
630
100
50
60
125
145
20
20
17.4
50
50
43.5
50
50
630
630
31.5
25
31.5
80
900
100
5 (10 operations)
20 (10 operations)
5000
2000
0.03
≤0.1%

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
6 EATON CORPORATION www.eaton.com
4.2. Rated current of the fuse:
Based on the capacity of the transformer, the rated current of the fuse is selected, as shown below.
(no overload, -25°C<0<40°C)
Transformer capacity
kVA
Rated current
A
Transformer capacity
kVA
Rated current
A
31.53151050
404001075
100
125
160
200
250
16
16
16
20
25
500
630
800
1000
1250
50
63
80
100
125
5. Standards
GB3906-2006
GB/T11022-1999
GB3804-2004
GB16926-1997
GB1984-2003
GB1985-2004
GB3309-1989
GB/T16927.1-1997
GB/T7354-2003
GB8905-1996
GB11023-1989
GB12022-1989
GB4208-1993
IEC 62271-100
IEC 62271-102
IEC 62271-105
IEC 62271-200
IEC 60694
IEC 60265-1
IEC 60529
3.6kV~40.5kV AC Metal Enclosed Switchgear and Controlgear
Common Technical Requirements of High Voltage Switchgear and Controlgear Standard
3.6kV~40.5kV High Voltage AC Load Switch
AC High Voltage Load Switch – Fuse Combination Unit
High Voltage AC Circuit Breaker
AC High Voltage Isolating Switch and Ground Switch
Mechanical Testing under Normal Temperature of High Voltage Switchgear
High Voltage Testing Technique Part 1: General Testing Requirements
Partial Discharge Measurement
Gas Management and Inspection Guideline of SF6 Electrical Equipment
SF6 Gas Sealing Test Guideline of High Voltage Switchgear
Industrial SF6
Housing Protection Degree (IP Code)
High-voltage switchgear and controlgear - Part 100: Alternating-current circuit-breaker
High-voltage switchgear and controlgear - Part 102: Alternating current disconnectors and
earthing switches (2003)
High-voltage switchgear and controlgear - Part 105: Alternating current switch-fuse
combinations for rated voltages above 1 kV up to and including 52 kV
High-voltage switchgear and controlgear - Part 105: AC metal-enclosed switchgear and
controlgear for rated voltages above 1 kV up to and including 52 kV
Common specifications for high-voltage switchgear and controlgear standards
High-voltage switches - Part 1: Switches for rated voltages above 1 kV and less than 52 kV
Degrees of protection provided by enclosures(IP Code)DL/T 592-2006 common
specifications for high-voltage switchgear and controlgear standard

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
7EATON CORPORATION www.eaton.com
6. Typical functions
A RMU of 12kV typical scheme is composed of three circuits - one
cable incoming circuit, one cable feeding circuit and one
combination unit outgoing circuit. The load switches on the cable
incoming circuit and the cable feeding circuit can reset the circuits
in time to resume power supply when isolating fault line
segments. The load switch and fuse of the combination unit
protect the downstream loads, while its load switch also conducts
opening-closing and isolation on the fuse and the downstream
loads.
The supply circuit of the RMU is operated in open loop.
The RUM is usually energized in the forms shown in Figure 1, 2
and 3.
Dual-power supplied ring network power supply system
Two-independent-power supplied ring network power supply system
The ring network power supply system with only one power supply
Note: a) “ ” RMU b) “K” open loop point
Figure 1
Figure 2
Figure 3

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
8 EATON CORPORATION www.eaton.com
7. Typical schemes and structures (see Figure 4, 5 and 6)
Figure 4 RMU structure diagram
Bus connector
RVAC-KKT RVAC-T
Load switch branch Combination unit branch

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
9EATON CORPORATION www.eaton.com
1. Busbar
2. Load break switch
3. Bus connector, Extension bushing
4. Spring operating mechanism
5. Incoming/outgoing cable bushing
6. Pressure relief device
7. Fuse tube
Figure 5 Sealed enclosure housing cross-section drawing
Figure 6-1 Basic schemes
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2
3
4
5
6
1
2
3
4
5
6
7

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
10 EATON CORPORATION www.eaton.com
Figure 6-2 Basic schemes
7.1. Overall structure
The typical scheme is a one/in-two/out three-section common
enclosure RMU, including one incoming, one ring feeder and one
ring outgoing.
The layout of the typical scheme is shown in Figure 4 (RVAC-KKT).
The overall structure is composed of two major parts, the
gas-filled sealed housing part and the non-gas-filled part such as
the control compartment, cable compartment, frame, and
pressure relief channel. The high voltage circuit is within the
gas-filled sealed housing, and the mechanism compartment is on
the top front, while the pressure relief channel is on the bottom
front. Fully shielding cable terminals are used for incoming and
outgoing lines.
7.2.1. Sealed housing
7.2. Component structure
The sealed enclosure housing is made of high-quality stainless
steel plates, using fully enclosed welding method and SF6 gas,
with the rated pressure of 0.03 MPa. During the whole running
life, safe operations can be maintained without the need to refill
the gas. After assembling, the gas-filled housing can not be drilled
nor welded.
7.2.2. Three-position Load switch
The three-position load switch is installed inside the gas-filled
housing, with its operating mechanism installed inside the control
compartment. The three-position load switch offers closing,
opening and grounding positions. The three-position load switch is
in the opening position when the knife is in the middle position.
The three-position load switch is in the closing position and ground
position separately when the knife is in the two-limit positions.
The load switch side and the ground switch side of the
three-position load switch are equipped with clear and reliable
mechanical opening/closing indicator (see Figure 7).

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
11EATON CORPORATION www.eaton.com
Closing position Opening position Grounding position
Figure 7 3-position opening/closing position indication
7.2.3. Fuse ground switch
The combination unit branch circuit (load switch + current limiting
fuse) is equipped with a fuse ground switch for linkage operations
with the three-position load switch, offering reliable grounding to
the fuse outgoing side. When the load switch is in closing/opening
operation, the fuse ground switch basically remains non-operating.
When the three-position load switch is in ground position, the fuse
ground switch makes reliable contact with the fixed contact base
at the fuse outgoing side, to ensure the fuse outgoing side is
reliably grounded.
7.2.4. Fuse
The fuse and the load switch constitute the transformer protection
circuit. Highly quickbreak current-limiting fuse is installed inside
the epoxy casting insulation housing. In the case of a short circuit,
after the fuse is blown out, the striker will be ejected to open the
load switch, enabling the fault line to be removed.
7.2.5. Frame
The frame (the housing except the sealing enclosure) is the basic
body of all the parts and components, to support and secure the
sealing enclosure. The frame uses aluminum- zinc plates formed
with multiple bendings, to be connected with high strength bolts,
nuts (Level 8.8) and rivets. The frame can be divided into three
main compartments: the control compartment, cable
compartment and pressure relief channel. There are a mechanism,
a fuse holder and a secondary circuit inside the control
compartment. The cable compartment contains a cable, its holder,
and the ground bus bar, with optional current transformer as
needed. The pressure relief channel is located behind the cable
compartment. On the front is located a pressure meter, a main
wiring mimic diagram, a voltage presence display, an operating
hole and operation buttons, a nameplate, a mechanism
compartment door, and a cable compartment door.
7.2.6. Mechanisms and their mechanical interlock
The three-position load switch is equipped with a spring operating
mechanism, offering reliable mechanical interlocking. The load
switch must be operated on according to specified operating
procedures.
Interlocking conditions are as follows:
Only when the load switch is moved to the opening position,
the ground switch can be closed;
Only when the ground switch is moved to the opening position,
the load switch can be closed;
Only when the ground switch is moved to the ground position,
the cable compartment door can be opened;
Only after the cable compartment door is closed, the ground
switch can be opened.
a.
b.
c.
d.

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
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1. Voltage presence indicator;
2. Meters;
3. Electric operating button and status indicating light;
4. Fault indicator;
5. Ground switch operating hole;
6. Loads switch status indication;
7. Ground switch status indication;
8. Cable compartment door interlocking device;
9. Load switch operating hole;
10. Main circuit mimic line;
11. SF6 gas pressure meter;
12. Combination unit manual release button;
13. Fuse status indication;
14. Fuse mimic line;
Figure 8
7.2.7. Simple and reliable operating interface
The operating mechanism has position indicator and mechanical
interlocking devices, with optional auxiliary contact, opening coil,
and electrical operating device, as shown in Figure 8.
7.2.8. Fuse Tube
The fuse tube mainly includes two parts: epoxy insulating tube and
locking plug, both of which are used to install and secure the fuse.
The epoxy insulating tube is installed on the sealed housing, itself
offering gas sealing feature to ensure the sealing performance of
the gas-filled housing. The fuse is secured on the locking plug with
screws, offering reliable insulation with close cooperation of the
silicone rubber locking plug and the epoxy insulating tube.

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
Pressure relief device
13EATON CORPORATION www.eaton.com
7.2.10. Ground circuit
The main grounding copper bar is supplied individually inside the
cable compartment, throughout the whole arrangement, for use
by directly grounded assemblies. The ground contact base of the
three-position load switch is connected with the main ground
copper bar with a copper bar, to constitute a ground circuit to
make the whole cabinet in a well grounding status, and ensure the
safety of the operators.
7.2.9. Pressure relief device
An explosion-proof sheet is equipped at the bottom of the sealed
enclosure housing. In the case of internal arcing fault, the high
pressure gas inside the housing can explode this sheet away to
release the pressure. Meanwhile, SF 6 gas will be released into
the ditch through the pressure relief channel to ensure the safety
of the operators. The pressure relief device is shown in Figure 9.
Figure 9

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
14 EATON CORPORATION www.eaton.com
Figure 10.1 Forklift handling example
Figure 10.2 Crane handling example
1. Transport and handling
Chapter 2 Transport, handling,
inspection and storage
1.1. The switchgear must be transported under the conditions that
the load switch is in “OFF” position, with its charging device
in “energy-releasing” state and the ground switch in “closed”
state.
1.2. The outer packing of the switchgear shall have anti-shock,
moisture-proof and dust-proof performance, and be adaptable
to railway and highway transportation.
1.3. In the case of handling by hand-push type forklift or by freight
forklift, the switchgear should be put onto the transportation
pallet (see Figure 10.1). In the case of crane handling, the
lifting hook of the crane should be hooked into the two lugs
on the top of the switchgear. The angle between the lifting
rope and the top of the cabinet shall exceed 45° (the angle
between the lifting rope and the plumb line shall not exceed
45 °), so as to avoid any deformation to the cabinet or the lug
(see Figure 10.2).
2. Inspection and storage
2.1. Visual inspection
Users shall make open-box inspections in a timely manner
after receiving the goods, to check the equipment for any
damages or deformation during transportation.
2.2. SF6 gas pressure inspection
When the product is delivered from the factory, SF6 gas has
been filled, with the gas relative pressure of 0.03 MPa. During
on-site inspection, the gas density meter will indicate whether
the pressure of the gas is normal (normal when the pointer
points to the green area, and abnormal when pointing to the
red areas).
2.3. Accessory inspection
After unpacking the package, please check whether the
equipment’s primary scheme conforms to the requirements
of the order, and whether the accessories are complete, such
as the equipment’s factory data, special opening tools, and
spare parts. In the case of any errors, please contact the
After-sales Service of Cooper Electric in a timely manner.
2.4. Storage
If the equipment can not be installed in time and has to be
stored for a period of time, use the original packaging
materials to properly pack the equipment after open-case
inspections, and store the equipment in a dry and clean place,
to avoid any mechanical damages to the equipment.
1.4. During loading and unloading, the switchgear shall be handled
according to the storage and transport indication mark on the
package, to avoid equipment damages. In general, the
switchgear should be moved vertically, to prevent from tilting
or turning over.
1.5. In the case of any damages found on the switchgear after
long-distance transportation, notify the cargo division
immediately to have the damage accidents identified.
CAUTION
IN THE CASE OF ABNORMAL GAS PRESSURE, NOTIFY THE AFTER-SALES
SERVICE OF COOPER ELECTRIC IN A TIMELY MANNER FOR DULY AND
PROPER HANDLING.
CAUTION
CHECK THE WEIGHT OF THE SWITCHGEAR. DO NOT USE WORN OUT
AND DAMAGED STEEL ROPES OR LIFTING RINGS. DO NOT USE THE
LIFTING EQUIPMENT WITH THE LIFTING CAPACITY LESS THAN THE
WEIGHT SHOWN ON THE NAMEPLATE OF THE SWITCHGEAR.

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
15EATON CORPORATION www.eaton.com
Figure 11
Chapter 3 Installation
1. RMU dimensions
RAVC-K, RVAC-T and RVAC-V are taken as examples for RMU
dimensions. See Figure 11.
CAUTION
THE PRODUCT SHALL BE INSTALLED BY PROPERLY TRAINED
PROFESSIONALS OR UNDER THE INSTRUCTION OF PROFESSIONALS.
RVAC-K RVAC-T RVAC-V
2. Base form
2.1. The RMU installation base shall be constructed in accordance
with relevant regulations in Technical Specifications for
Electric Power Construction and Acceptance Inspection.
2.2. The RMU’s installation base is generally poured with concrete
twice. For the first time, concrete the installation base of the
RMU’s installation elements including the angle steel, square
steel and channel steel. For the second time, concrete the
ground supplement layer, with a common thickness of 60
mm. When pouring concrete to the supplement layer, the
height of the concrete should be 1 ~ 3 mm lower than the
element surface.
KTV
12kV Width 370 370 480
Depth 800 800 800
Height 1400 1400 1400
24kV Width 370 370 520
Depth 870 870 870
Height 1400 1400 1400
1400
725
Width
110 110
110 110
Width
452
1400
Width
130 130
603
1400
1740

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
16 EATON CORPORATION www.eaton.com
Figure 12.1 RMU indoor installation base dimension
Figure 12.2 The frame installation base at the RMU side
2.3. For the dimensions of the RMU installation bases, see Figure 12.1 and Figure 12.2 (12kV cabinet depth 800mm,
24kV cabinet depth is 870mm).
2.4. To ensure the installation quality of the basic elements, the levelness of the framework
installation requires the tolerance of 1 square meter shall be less than 3 mm.
Rated voltage (kV)
Size (mm)
12
24
A
730
800
B
680
730
CDEFGHI
633.5
683.5
750
800
700
750
480
520
430
470
62
82
58
8
KM TV
A
(Chassis)
B (8# steel channel)
C
H
I
D370 370
34.5
525
23.5 30
320 32025 50 5050E
6-Ø14 Unit
This row of
mounting holes
is available
as an option
F
G
The front of the switchgear
Size (mm)
800 (12kV)
870 (24kV)
(8# steel
channel)
(8# steel
channel)
Chassis
M8 x 30
B
III
I
II
M8 x 30
800~1000
10
1740
1400
23.5
Chassis
The front of the switchgear

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
17EATON CORPORATION www.eaton.com
Figure 13 Grounding position diagram
3. RMU fixation
3.1. The bottom of the switchgear is linked to the metal base
frame with bolts, enabling the switchgear to be fixed on the
frame (the cabinet shall have 4 connection joint surfaces with
the frame). Use M20 connecting screws and bolts, with the
torque of 40 + 4 Nm.
4. RMU grounding
The grounding bar of the RMU must be connected to the
grounding grid of the site. The grounding position of the RMU is
inside the right side frame of the cabinet chassis. See Figure 13.
Use M12 connecting screws or bolts, with the torque of 70
±7Nm. The grounding wire is not included in the supply scope.
3.2. Check all the fastening bolts for looseness, and all the wirings
for reliability.
3.3. Check whether the 3-position load switch mechanism can be
operated flexibly, whether the load switch can open and close
freely; check for any abnormity. Check whether the interlocks
are reliable.
WARNING
THE CHARGING DEVICE SHALL NOT BE IN CHARGING STATE DURING
THE INSTALLATION AND CONNECTION OF THE RMU. OTHERWISE, THIS
MAY CAUSE PERSONAL INJURY.

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
18 EATON CORPORATION www.eaton.com
Figure 14.1 Ground switch status indication
Figure 14.2 Cable compartment door interlocking device
5.1. Preparation prior to cable placing
5. Cable installation
Remove the cable compartment door in the procedures shown
below (for the operating method of the switch, see Chapter 4)
Operate and confirm the ground switch is in the closed state
(see Figure 14.1);
Lift up the interlocking device, and release the lockout of the
cable compartment door (see Figure 14.2);
Remove the cable compartment door, and open the cable
compartment (see Figure 14.3);
a.
b.
c.

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
Red-colored
dust cap
19EATON CORPORATION www.eaton.com
Figure 14.3 Removal of the cable compartment door
WARNING
PLEASE READ CAREFULLY THE INSTALLATION INSTRUCTION MANUAL
OF THE CABLE ACCESSORIES. ONLY PROFESSIONAL INSTALLATION
PERSONNEL ARE ALLOWED TO MAKE THE ACCESSORY STRICTLY
ACCORDING TO ITS REQUIREMENTS. FAILURE TO DO SO WILL SEVERELY
AFFECT THE NORMAL OPERATION OF THE EQUIPMENT.
WARNING
THE INSTALLATION OF THE CABLE BRACKETS AND THE FIXATION OF
THE CABLE SHALL NOT BRING ADDITIONAL FORCES TO THE
INSULATING CASING.
5.2. Cable connection
The cable terminal head adopts prefabricated silicone rubber, with
well-designed internal stress cone and shielding, properly solving
electric field concentration issues at the cutting place of the outer
screen and at the high voltage end. There is a semi-conductive
layer outside the product, allowing the live parts to be fully sealed,
fully insulated and completely screened, thus ensuring reliable
operations of the ring main unit. The load switch casing is 725 mm
away from the ground, while the combination unit cabinet casing
is 452 mm away from the ground, well protected by the cable
compartment door. Passing through the cable trench into the
cabinet, the cable are cut off after the length is measured. The
connections of relevant parts and the making of cable heads shall
be considered as far as the length is concerned.
WARNING
RED-COLORED PROTECTIVE DUST CAP IS FORBIDDEN TO BE PUT INTO
OPERATION, AND CAN NOT REPLACE THE INSULATION COVER FOR USE.

Instruction Leaflet IL0102002E
Effective April 2018
Ring Main Unit Operation Instruction
1. Locking plug; 2. Sealed housing; 3. Fuse; 4. Fuse cylinder; 5. Pull handle
20 EATON CORPORATION www.eaton.com
Figure 15 Fuse cylinder structure drawing
Figure 16 Fuse cylinder operation example
6. Fuse installation (equipped with the fuse’s transformer feeder unit)
The fuse shall be installed and replaced by properly trained
professionals.
Before the RMU is put into operation, properly install the chosen
fuse as described in the following procedures:
Open the combination unit branch load switch;
Move the 3-position load switch to the ground position, to
ensure that both ends of the fuse are grounded;
As shown in Figure 16, move the handle from the vertical
place to horizontal place, maintain and withdraw the locking
plug horizontally. Handle with care, to avoid any damage to the
fuse cylinder;
a.
b.
c.
Check the silicone rubber sleeves for any damage, and the
contact button on the locking plug for any permanent
deformation;
Install a new fuse, ensuring a dimension of 2 to 4mm as shown
in Figure 17. Check whether the installation direction is correct,
because the fuse’s striker pushes the load switch to open after
the fuse is blown. Therefore, the striking end of the fuse (small
end) must be outward;
d.
e.
Pull up the handle
to replace the fuse