This help page is intended as a guide for integrators and users of the WASP series products who want to monitor gas meters. This help page must be read in conjunction with relevant rules & regulations pertaining to the location of intended use of the WASP device. The regulations for connecting to gas meters for each state, territory and gas authority are subject to change and this document may not reflect changes acccurately. Outpost does not take responsibility for the accuracy of information contained on this page.
Refer to "S004 WASP-EX Product Code Variants" for a complete list of instrinsically safe WASP variants.
Outpost loggers can be used to monitor gas meters either by using a WASP-EX Intrinsically Safe variant (subject to agreement by the meter owner that hazardous safety zone requirements are met) or by using a normal an Outpost WASP, WASP2 or EVO series loggers in conjunction with an appropriate Intrinsically Safe barrier device (IS Barrier), where the IS barrier is suitable for the hazardous safety zone rating of the meter, and the gas meter owner agrees that the rating is suitable.
The WASP-EX series loggers potentially provide a lower-cost option for monitoring gas meters due to:
- no IS barrier is required (subject to agreement by gas meter owner)
- no waterproof housing required for the WASP or IS barrier (WASP device is IP68)
Connecting to Gas Meter with WASP-EX Series Loggers
The Outpost WASP-EX series loggers have been certified with certificate number IECEx ITA 12.0033X as at 17-Jan-2013, issued by TUV Rhineland. The certificate is for type of protection "IS", with marking "Ex ib IIC T4 Tamb -20oC to + 60oC".
The status and authenticity of this certificate may be verified by visiting the Official IECEx Website. View the certificate using this link: http://iecex.iec.ch/iecex/iecexweb.nsf/welcome and searching for IECEx ITA 12.0033X in the "Quick Access" text box. If required, please request a copy of the official certificate from Outpost Central.
The following documents are available for reference when using WASP-EX series loggers. The S005 WASP-EX Product Instructions must be supplied with the WASP-EX product. S005 contains instructions relating to the attachment of the WASP-EX device to physical inputs, and cleaning instructions to avoid static buildup (clean with a damp cloth - never a dry cloth).
S002 WASP-EX Marking detail - Rev3.pdf
S003 WASP-EX General Assembly drawing - RevH.PDF
S004 WASP-EX Product Code Variants - Rev4.pdf
S005 WASP-EX Product Instructions - Rev1.pdf
The "ib" part of the IEC EX marking refers to the "protection concept" and indicates that the WASP-EX series loggers are certified for use in areas classed as Zone 1 or Zone 2. Broadly speaking the zone refers to areas where:
Zone 0: A hazard is constantly present (not an official definition)
Zone 1: There is a high possibility of a hazardous atmosphere being present (not an official definition)
Zone 2: Hardardous atmosphere is possibly present in a fault condition (not an official definition)
Most gas meter owners class their gas meters in accordance with their local regulations as "Zone 1" or "Zone 2", but this classification is determined by the gas meter owner and may differ between different states and gas authorities.
Therefore, integrators must confirm with the gas meter owner that the rating of the WASP-EX device is sufficient to allow connection of the WASP-EX logger to the meter owners gas meter.
Attaching Physical Inputs, Cables & Connectors to WASP-EX Variants
The following text is reproduced from "S005 WASP-EX Product Instructions - Rev1":
Attachment of Physical Inputs
The Outpost WASP-EX is designed to interface to gas flow meters and some types of 4-20mA sensors. For operation in a hazardous area where the Outpost WASP-EX is permitted to function, any attached devices must
also be certified by an approved competent person as safe to operate in conjunction with the Outpost WASP-EX in the given hazardous environment.
To be approved as safe for attachment to the WASP-EX by a competent person, the attached meter/sensor interface device must either be deemed to be a “simple apparatus”, or else it must carry its own safety rating issued by an
approved certifying body.
Attachment of a “Simple Apparatus”
Reed-switches, connectors or other passive devices that output flow information from a meter can usually be deemed as a “simple apparatus” and therefore do not require a specific safety rating.
However, only an approved competent person can deem a reed switch, connector or other passive device to be a “simple apparatus”.
Any simple apparatus attached to a particular channel on the WASP-EX must not have an inductance value that, when combined with the WASP-EX input channel inductance, exceeds 22uH.
For all WASP-EX variants the inductance of the specific input channel does not exceed 3uH per meter of intrinsic WASPEX channel cable length, up to a maximum of 5m length, or 15uH.
Refer to the specific product code variant in the “S004 WASP-EX Product Code Variants” document to find the inductance value of the specific WASP-EX input channel cable.
Attachment of an Electronic Meter/Sensor
4-20mA sensors, electronic meters, transistor-based output meters, or other electronic meters & sensors may be attached to the Outpost WASP-EX provided:
- The device has its own safety rating that meets the minimum requirements for the given hazardous area
- An approved competent person approves the attachment of the device.
- The device does not have its own internal power source and is powered by the Switched Power Output (SPO) channel on the WASP-EX variant.
- When attached to a particular channel of the WASP-EX, the device must not have an inductance value such that, when combined with the WASP-EX input channel inductance, exceeds 22uH. Refer to the specific product code variant in the “WASP-EX Product Code Variants” document to find the inductance of the input channel cable.
For all WASP-EX variants the inductance of the specific input channel does not exceed 3uH per meter of intrinsic WASP-EX
channel cable length, up to a maximum of 5m length, or 15uH.
Attachment of Cable Extensions & Connectors
As implied by the official text from S005, cable extensions and connectors are allowed to be fitted to the WASP-EX variant provided that cable extension do not exceed the ratings described, and provided that connectors are certified as simple apparatus by the relevant gas meter owner.
It is the responsibility of the party fitting the cable extension and/or connector to check ratings are not exceeded (in the case of cable extension) and that meter owners approve connectors (in the case of attaching connectors).
When a connector extension cable in required for a WASP-EX device, the relevant clause is noted for each variant described in the S004 document: "Note 5: The maximum capacitance will not exceed 0.5nF per meter, and the maximum inductance will not exceed 3uH per meter for maximum of 5m, for each input cable. 3uH/m measured when cable coiled to no less than 100mm diameter."
This means your certified gas-fitter can attach any cable to the device as long as it doesn't exceed 5m and doesn't exceed the stated capacitance and inductance per meter.
It is possible to arrange for connectors or plugs to be fitted to the WASP-EX variants (such as the M12 IP68 cables that are made available with the -ENV WASP options), however the owner of the gas meter must approve the proposed connector. as a simlpe apparatus as per S005. To do this the proposed connector spec sheets must be sent to the gas meter owner so they can approve the connector as a "simple apparatus" with insufficient inductance and capacitance to affect the IEC Ie rating of the WASP-EX device.
Connecting to Gas Meter using WASP + Intrinsically Safe Barriers
Intrinsically Safe "IS" barriers such as the MTL7710+ can be used to connect a normal WASP series device to a gas meter. The IS barrier may be required to be housed in a water-proof casing.
In New Zealand, fully isolated barriers (chatterboxes), or IS barriers that attach to battery powered equipment do not require an earth connection (27-Jun-2012). This may be applicable in Australia at the discretion of the gas meter owner.
If a logger that is battery powered and has no connection to earth, then the chosen IS barrier in turn also does not require a connection to earth.