WIKA GDM-RC-100-T User manual

Operating instructions
Betriebsanleitung
EN
DE
Hybrid gas density monitor with reference chamber, model GDM-RC-100-T
Hybrid-Gasdichtewächter mit Referenzkammer, Typ GDM-RC-100-T
Hybrid gas density monitor with
integrated transmitter Hybrid gas density monitor with attached transmitter

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WIKA operating instructions, model GDM-RC-100-T
EN
DE
Operating instructions model GDM-RC-100-T Page 3 - 44
Betriebsanleitung Typ GDM-RC-100-T Seite 45 - 85
© 01/2022 WIKA Alexander Wiegand SE & Co. KG
All rights reserved. / Alle Rechte vorbehalten.
WIKA®is a registered trademark in various countries.
WIKA®ist eine geschützte Marke in verschiedenen Ländern.
Prior to starting any work, read the operating instructions!
Keep for later use!
Vor Beginn aller Arbeiten Betriebsanleitung lesen!
Zum späteren Gebrauch aufbewahren!

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Contents
Contents
1. General information 4
2. Design and function 5
3. Safety 6
4. Transport, packaging and storage 13
5. Commissioning, operation 14
6. Faults 31
7. Maintenance, cleaning and recalibration 33
8. Dismounting, return and disposal 34
9. Specifications 35
Declarations of conformity can be found online at www.wika.com

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1. General information
■The gas density monitor described in the operating instructions has been designed
and manufactured using state-of-the-art technology. All components are subject
to stringent quality and environmental criteria during production. Our management
systems are certified to ISO 9001 and ISO 14001.
■These operating instructions contain important information on handling the instru-
ment. Working safely requires that all safety instructions and work instructions are
observed.
■Observe the relevant local accident prevention regulations and general safety regula-
tions for the instrument's range of use.
■The operating instructions are part of the product and must be kept in the immediate
vicinity of the instrument and readily accessible to skilled personnel at any time. Pass
the operating instructions on to the next operator or owner of the instrument.
■Skilled personnel must have carefully read and understood the operating instructions
prior to beginning any work.
■The general terms and conditions contained in the sales documentation shall apply.
■Subject to technical modifications.
■Further information:
- Internet address: www.wika.de / www.wika.com
- Relevant data sheet: SP 60.80 (model GDM-RC-100-T)
SP 61.16 (model GLTC-CV)
- Application consultant: Tel.: [phone]
Fax: [phone]
[e-mail]
1. General information

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2. Design and function
2.1 Overview
Electrical connection, cable socket
Transmitter
Lasered product label
Process connection
2.2 Description
The microswitch contacts permanently built into the gas density monitor act as change-
over contacts and switch if compensated limiting pressure values have been set.The
microswitch contacts are actuated by a bellows system integrated into the instrument
when the gas density value drops and rises.The integrated or attached transmitter
transmits the measured value via an analogue or digital output signal.
2.3 Scope of delivery
Cross-check scope of delivery with delivery note.
Hybrid gas density monitor with
integrated transmitter
Hybrid gas density monitor with
attached transmitter
 



2. Design and function

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3. Safety
3.1 Explanation of symbols
WARNING!
... indicates a potentially dangerous situation that can result in serious injury
or death, if not avoided.
CAUTION!
... indicates a potentially dangerous situation that can result in light injuries
or damage to property or the environment, if not avoided.
Information
... points out useful tips, recommendations and information for efficient
and trouble-free operation.
3.2 Intended use
The intended use of model GDM-RC-100-T is to monitor the gas density of insulating
gases.
Wherever the gas density of SF₆ gas must be indicated locally and, at the same time,
circuits need to be switched, the model GDM-RC-100-T hybrid gas density monitor finds
its use.
The integrated or attached digital transmitter transmits the parameters of gas density,
pressure and temperature as electrical signals via the Modbus®-RTU protocol.
The integrated or attached analogue transmitter transmits the absolute pressure refer-
enced to 20 °C [68 °F] or the gas density in g/l for SF₆ gas as a 4 ... 20 mA signal.
Gas density monitors are modified pressure measuring instruments with switch contacts,
specially developed for the use of SF₆ gas and other insulating gases. Temperature influ-
ences acting on the enclosed gas are compensated by a compensation system.
The gas density monitors are specially designed for the respective application in switch-
gear (pure SF₆ gas, gas mixtures, calibration pressure, switch points ...). Before use, check
whether this instrument is suitable for the intended application.
The insulation values (air gaps and creepage distances) are sized for the following
ambient conditions in accordance with EN 61010-1:2010:
■Altitude up to 2,000 m
■Overvoltage category II
■Pollution degree 2
■Relative humidity: 0 ... 95 % non-condensing (per DIN 40040)
Only use the instrument in applications that lie within its technical performance limits
(e.g. max. ambient temperature, material compatibility, ...).
→ For performance limits, see chapter 1 “General information”.
3. Safety

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This instrument is not permitted to be used in hazardous areas!
The instrument has been designed and built solely for the intended use described here,
and may only be used accordingly.
The technical specifications contained in these operating instructions must be
observed. Improper handling or operation of the instrument outside of its techni-
cal specifications requires the instrument to be taken out of service immediately and
inspected by an authorised WIKA service engineer.
The manufacturer shall not be liable for claims of any type based on operation contrary
to the intended use.
3.3 Improper use
WARNING!
Injuries through improper use
Improper use of the instrument can lead to hazardous situations and
injuries.
▶Refrain from unauthorised modifications to the instrument.
▶Do not open the instrument while under voltage.
▶Do not use the instrument within hazardous areas.
The instrument must not be subjected to any external loading (e.g. use as a climbing
aid, support for objects).
Any use beyond or different to the intended use is considered as improper use.
3.4 Responsibility of the operator
The instrument is used in the industrial sector.The operator is therefore responsible for
legal obligations regarding safety at work.
The safety instructions within these operating instructions, as well as the safety, accident
prevention and environmental protection regulations for the application area must be
maintained.
The operator is obliged to maintain the product label in a legible condition.
To ensure safe working on the instrument, the operating company must ensure
■that suitable first-aid equipment is available and aid is provided whenever required.
■that the operating personnel are regularly instructed in all topics regarding work safety,
first aid and environmental protection and know the operating instructions and, in
particular, the safety instructions contained therein.
■that the instrument is suitable for the particular application in accordance with its
intended use.
■that personal protective equipment is available.
3. Safety

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3.5 Personnel qualification
WARNING!
Risk of injury should qualification be insufficient
Improper handling can result in considerable injury and damage to
property.
▶The activities described in these operating instructions may only be
carried out by skilled personnel who have the qualifications described
below.
Skilled personnel
Skilled personnel, authorised by the operator, are understood to be personnel who,
based on their technical training, knowledge of measurement and control technology
and on their experience and knowledge of country-specific regulations, current stand-
ards and directives, are capable of carrying out the work described and independently
recognising potential hazards.
Specically when using SF₆ gas
The operator must ensure that the SF₆ gas is handled by a company qualied for this or
by employees trained in accordance with IEC 62271-4 or IEC 60480 chapter 10.3.1.
3.6 Personal protective equipment
The personal protective equipment is designed to protect the skilled personnel from
hazards that could impair their safety or health during work.When carrying out the
various tasks on and with the instrument, the skilled personnel must wear personal
protective equipment.
Follow the instructions displayed in the work area regarding personal protective
equipment!
The requisite personal protective equipment must be provided by the operating company.
Safety goggles in accordance with EN 166, class 2, mechanical
strength class S
Safety goggles must be worn during the entire period when working on
hoses or gas containers (e.g. gas cylinders, tanks).
The safety goggles protect the eyes from any flying particles, escaping
gas and liquid splashes.
Protective gloves against heat in accordance with EN ISO 13732-1
and against cold in accordance with EN ISO 13732-3
The protective gloves must be worn over the entire period when working
on hoses, gas containers (e.g. gas cylinders, tanks) or components which
heat up to over 60 °C [140 °F].
3. Safety

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3.7 Handling of insulating gases and gas mixtures
SF₆ gas is a greenhouse gas which is listed in the Kyoto Protocol. SF₆ gas must not be
released into the atmosphere, but must be collected in suitable containers.
Properties of insulating gases
■Colourless and odourless
■Chemically neutral
■Inert
■Not flammable
■Heavier than air
■No toxicity
■No damage to the ozone layer
Detailed information is given in IEC 60376 and IEC 62271-4.
Danger of suocation caused by insulating gases and gas mixtures
High concentrations of gases can lead to asphyxiation, since breathable air is displaced
from the lungs with the inhalation of gas.
Since SF₆ gas is heavier than air, it collects, especially, at ground level or lower-lying
rooms below the reference level (e.g. cellars). This is particularly dangerous since SF6
gas is colourless and odourless and thus may be imperceptible to people.
3.8 Danger caused by decomposition products
Insulating gas in electrical systems may contain decomposition products generated by
electric arcs:
■Gaseous sulphur fluorides
■Sulphur hexafluorides
■Solid and atomized metal fluorides, metal sulphides, metal oxides
■Hydrogen fluoride
■Sulphur dioxide
Decomposition products can be harmful to health.
■They can cause poisoning by inhalation, ingestion or contact with the skin.
■They may be irritating to the eyes, the respiratory system or the skin and burn them.
■Inhalation of large quantities may damage the lungs.
Observe the following safety instructions in order to avoid danger from insulating gas:
■Wear personal protective equipment.
■Read the material safety data sheet of the gas supplier.
■With large leakage, evacuate the area quickly.
■Ensure good ventilation.
■Ensure the leak tightness of the equipment with a leak detector (e.g. model GIR-10).
3. Safety

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3. Safety
3.9 Applicable standards and directives for installation, assembly, commissioning:
Installation, assembly, commissioning:
■BGI 753 (SF₆ plants and equipment in Germany)
■IEC 62271-4 (Handling of SF₆ gas)
■IEC 60376 (New SF₆ gas, technical grade SF₆ gas)
■IEC 60480 (Used SF₆ gas)
■CIGRE report 276, 2005 (Practical SF₆ gas handling instructions)
■Leakages during operation:
■IEC 60376 (New SF₆ gas, technical grade SF₆ gas)
■IEC 60480 (Used SF₆ gas)
■CIGRE 2002 (“SF₆ gas in the electrical industry”)
Repair work and maintenance:
■IEC 62271-4 (Use and handling of SF₆ gas in high-voltage switchgear and controlgear)
■CIGRE 1991 (Handling of SF₆ gas)
■CIGRE report 276, 2005 (Practical SF₆ gas handling instructions)
Information
SF6 is a colourless and odourless, chemically neutral, inert and non-amma-
ble gas which is approx. ve times heavier than air, non-toxic and not harmful
to the ozone layer.
Detailed information is given in IEC 60376 and IEC 62271-4.

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3.10 Labelling, safety marks
Product label, model GDM-RC-100-T with integrated transmitter (example)
Model description
Output signal
IP class
Date of manufacture
Article number
Pin assignment
Supply voltage
Permissible ambient temperature
Measuring range
Number and position of switch points
WIKA Alexander Wiegand SE & Co. KG
63911 Klingenberg









3. Safety

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3. Safety
Product label, model GDM-RC-100-T with attached transmitter (example)
Model description
IP class
Date of manufacture
Article number
Supply voltage
Permissible ambient temperature
Measuring range
Number and position of switch points
Product label of the attached transmitter (example)
Model description
Measuring range compensated pressure
Density equivalent of the full scale of compensated pressure
Pin assignment
Logos
Coded date of manufacture
Temperature range
Communication
Supply voltage
Gas mixture
P# article number
S# serial number
WIKA Alexander Wiegand SE & Co. KG
63911 Klingenberg







GD-20-A
DE-63911 Klingenberg
Made in Germany







11
11

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Before mounting and commissioning the instrument, ensure you read
the operating instructions!
4. Transport, packaging and storage
4.1 Transport
Check the gas density monitor for any damage that may have been caused by transport.
Obvious damage must be reported immediately.
CAUTION!
Damage through improper transport
With improper transport, a high level of damage to property can occur.
▶When unloading packed goods upon delivery as well as during internal
transport, proceed carefully and observe the symbols on the packaging.
▶With internal transport, observe the instructions in chapter 5.2 “Packag-
ing and storage”.
4.2 Packaging and storage
Do not remove packaging until just before mounting.
Keep the packaging as it will provide optimum protection during transport (e.g. change
in installation site, sending for repair).
WARNING!
Physical injuries and damage to property and the environment
caused by hazardous decomposition products
Before storing the instrument, any residual decomposition products must
be removed.
▶For cleaning, see chapter 7.2 “Cleaning”
Permissible conditions at the place of storage:
■Storage temperature: -40 ... +70 °C [-40 ... +158 °F]
■Humidity: ≤ 95 % r. h. (no condensation)
Avoid exposure to the following factors:
■Soot, vapour, dust and corrosive gases
■Hazardous environments, flammable atmospheres
Store the instrument in its original packaging in a location that fulfils the conditions
listed above. If the original packaging is not available, pack and store the instrument as
described below:
1. Place the instrument, along with the shock-absorbent material, in the packaging.
2. If stored for a prolonged period of time (more than 30 days), place a bag containing
a desiccant inside the packaging.
3. Safety / 4.Transport, packaging and storage

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5. Commissioning, operation
5.1 Mechanical mounting
CAUTION!
Physical injuries and damage to property and the environment
through faulty instrument
Prior to commissioning, the instrument must be subjected to a visual
inspection.
▶Only use the instrument if it is in perfect condition with respect to safety.
5.1.1 Requirements for the installation point
■For outdoor applications, the selected installation location has to be suitable for the
specified ingress protection, so that the instrument is not exposed to impermissible
weather conditions.
■The sealing faces at the instrument and at the measuring location have to be undam-
aged and clean.
The measuring instruments must be mounted in the common mounting position per
EN 837-1, with a max. permissible incline of 5° on all sides.
The measuring location should preferably be positioned directly at the
gas compartment. A measurement at the end of measuring lines prevents
optimal results through unwanted temperature differences to the main tank.
5.1.2 Installation
■
With transport or storage, it can occur that gas density monitors warm up or cool down
and this results in pointer movements.These pointer movements are caused by the
compensation system. To make sure that the instruments have adapted sufficiently
to ambient temperature, at least 2 hours at 20 °C [68 °F] must be allowed for adapta-
tion to the temperature. Then, in the depressurised state, the pointer will sit within the
tolerance bar.
■
Corresponding to the general technical rules for pressure gauges (e.g. EN 837-2
“Selection and installation recommendations for pressure gauges”) when screwing in
the instrument, the force required to do this must not be applied through the case, but
only through the spanner flats provided for this purpose and using a suitable tool.
■
When screwing in, do not cross the threads.
For parallel threads, use flat gaskets, lens-type sealing rings or WIKA profile sealings at the
sealing face . With tapered threads (e.g. NPT threads), sealing is made in the threads ,
using a suitable sealing material (EN 837-2).
The tightening torque depends on the sealing used. In order to orientate the measuring
instrument so that it can be read as well as possible, a connection with LH-RH adjusting
nut or union nut should be used.When a blow-out device is fitted to an instrument, it must
be protected against being blocked by debris and dirt.
5. Commissioning, operation

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5.1.3 Temperature load
The installation of the instrument should be made in such a way that the permissible
operating temperature, also considering the effects of convection and thermal radiation,
neither exceeds nor falls below the permissible limits.
The temperature effect on the indication and measurement accuracy must be observed.
5.2 Electrical connection
5.2.1 Connection lead
With the selection of connection leads, the following points must be noted:
■Conductor cross-section must be selected corresponding to the load current/overcur-
rent protection device.
■The sealing range of the supplied cable gland must fit the conductor diameter.
■The temperature range of the cable must correspond, as a minimum, to the operating
temperature range of the instrument.
→ For specifications, see chapter 9 “Specifications”.
5.2.2 Grounding
■
The main instrument must be grounded via the process connection.
■Fasten the protective conductor of the connection cable for the switch contacts to the
terminal (1) provided for this purpose as shown in the figure below.
■Never remove the protective conductor connection cable (2) between the main
instrument and the counterpart of the cable socket. Otherwise, operational safety
cannot be ensured.
Sealing in the thread 
Spanner ats
Sealing face 
5. Commissioning, operation

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5.2.3 Connection terminals and wire preparation of the switch contacts
4-pin terminal: Connection of the transmitter
12-pin TTI plug-in terminal: Connection of the switch contacts
CAUTION!
Damage to the instrument through incorrect connection
Connecting the switch contacts or the transmitter to the wrong cable termi-
nals can lead to irreversible damage to the instrument.
▶Ensure that the pin assignment is correct.
The connection terminals are suitable for the following types of single conductor or cross-
sections:
Connection terminals and wire preparation
Connection terminals of
the socket terminal strip
for the switch contacts
Connection terminals of
the protective conductor
Types of single
conductors
■Solid wire core
■Flexible stranded wire
■Flexible stranded wire with end
splice
■Solid wire core
■Flexible stranded wire with end
splice
Wire length ≥ 90 mm ≥ 120 mm
Maximum length of
the bare wire end
Max. 5.5 mm Max. 8 mm
Number of wires /
Cross-sections
1 x 0.5 mm² to 1 x 2.5 mm²
Recommended
tightening torque
0.5 Nm 1.2 Nm
5. Commissioning, operation

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5.2.4 Switch contacts
■The position of the switch points and the switching functions are indicated on the
product label.
■The assignment of the individual switching functions is marked on a sticker affixed to
the mating connector at the terminal:
Wiring scheme
First digit ■1x – Switch contact S1
■2x – Switch contact S2
■3x – Switch contact S3
■4x – Switch contact S4
Second digit ■x1 – Common
■x2 – Normally closed
■x3 – Normally open
Wiring scheme
S4S3S2S1
12 13 11 21 23 22 32 33 31 41 43 42
Status of switching output: Not pressurised
GDM-RC-100-T
Terminal
Wiring scheme
5. Commissioning, operation

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Schematic diagram of the switch behaviour with rising or falling gas density over time:
The actual order of the switch points is customer-specific.
If the gas density monitor is not pressurised, all contacts are not actuated mechanically.
Fourth switch point: Pin 41 is connected to pin 42 (1).
If the gas density monitor is pressurised, an overtravel of the switch point will switch the
switch contact from pins 41-42 to pins 41-43.
The switch contact will not be switched back from pins 41-43 to pins 41-42 until the
value drops below the switching threshold.
Up to four switch contacts allow all desired switching functions to be completely
covered. Depending on the application requirement, falling closing, falling opening,
rising closing or rising opening can be switched.
The switch contacts are adjusted for either falling or rising density.
It is recommended to always switch only in the switching direction adjust-
ed ex-works, since otherwise the switch hysteresis of the switch contact
also has to be taken into account.
→ For detailed information regarding hysteresis, see data sheet SP 60.80
SP1
SP2
SP3
SP4
P@ 20 °C
t
S1
S2
S3
S4
11 - 13
11 - 12
21 - 23
21- 22
31 - 33
31 - 32
41 - 43
41 - 42



Switches Terminals
5. Commissioning, operation

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Examples for switching functions in the application
1. Example with three contacts as normally closed: Contacts 1 and 2 should open when
value drops below threshold, and contact 3 should open when threshold is exceeded:
2. Example with two contacts as normally open: Contacts 1 and 2 should close when
values drops below threshold:
S3S2S1
12 13 11 21 23 22 32 33 31 41 43 42
Status of switching output: Not pressurised
GDM-RC-100-T
Terminal
Connection example - three contacts
Falling
opening
Falling
opening
Rising
opening
S2S1
12 13 11 21 23 22 32 33 31 41 43 42
GDM-RC-100-T
Terminal
Falling clos-
ing
Falling clos-
ing
Connection example - two contacts
Status of switching output: Not pressurised
5. Commissioning, operation

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5.2.5 Closing the cable socket
■Ensure that no moisture can enter at the cable end.
■For this, make sure that the cable gland of the fitted case cover fits the diameter of
the cable used and that the cable gland is correctly seated.
■Make sure that the seals are present and undamaged.
■Tighten the cable gland with the torque specified in the specifications (→ see chapter
9 “Specifications”) and check that the seal is correctly seated, in order to ensure the
ingress protection.
5.2.6 Limit values for the contact load with resistive load
Do not exceed the limit values.
The switching current must not be less than 10 mA with low voltages (12 V) for switching
reliability reasons.
Overcurrent protectors
The instruments do not provide for incorporated overcurrent protectors.Therefore,
overcurrent protectors with the following nominal values must be used on the system side:
■Max. 5 A (at Ta: -40 … +70 °C [-40 ... +158 °F])
■Max. 1 A (at Ta: > 70 … 80 °C [-40 ... +176 °F])
If overcurrent protectors in accordance with EN 60127-2 or equivalent
are used, these must be selected with a high breaking capacity (e.g.
H1500A).
5.2.7 Contact protection measures
Mechanical contacts must not exceed the specified electrical values for switching
current, switching voltage and switching power independent of each other, not even for
a short time only.
For capacitive or inductive loads one of the following protective circuits is recommended:
Inductive load with DC voltage
With DC voltage the contact protection can be achieved via a free-wheeling diode,
connected in parallel to the load.The polarity of the diode must be arranged so that it
closes when the operating voltage is on.
Example:
Contact protection
measure with free-wheel-
ing diode
Contact
Diode Load
5. Commissioning, operation