Fluke 1630-2 FC Stakeless Earth Ground Clamp

Fluke 1630-2 FC stakeless earth ground loop and leakage current clamp

The Fluke 1630-2 FC is a clamp-style earth ground tester that measures earth loop resistance without driving a single test stake, and also reads ac leakage current in the earthing conductor. Unlike a stake-based instrument such as the Fluke 1625-2, the 1630-2 FC works by clamping onto an earth rod, bus bar or ground wire inside a multi-grounded system, so it can test where the ground is paved over, inside a building or on a structure. Seven Star LLC supplies the 1630-2 FC in Oman and the GCC as an independent supplier in Muscat, and the sections below explain the method, the data sheet figures and the points to confirm before an RFQ.

How the 1630-2 FC measures loop resistance

The jaw of the clamp contains two sections. One induces a known voltage into the conductor, and the other senses the resulting current. From these two values the clamp calculates the resistance of the loop through that conductor and the rest of the earthing system. Because no auxiliary stakes are used, the earth electrode does not need to be disconnected from the system. The manufacturer points out that the technique avoids the hazardous and time-consuming job of disconnecting parallel grounds. It follows that a loop must exist: the method suits multi-grounded systems where many parallel paths form a return, and it does not replace a fall-of-potential test on an isolated single electrode.

Technical specifications of the 1630-2 FC

Leakage current measurement and the band-pass filter

The same clamp can measure ac leakage current in an earthing conductor without disconnecting the earth stake, which helps when troubleshooting a system for stray currents. The data sheet lists autoranging from 0.200 mA to 39.99 A at 50/60 Hz, true rms with crest factor up to 3. A selectable band-pass filter removes unwanted noise from the leakage measurement; with the filter on the specified frequency range is 40 to 70 Hz, and with the filter off it is 40 Hz to 1 kHz. The clamp is also specified to IEC/EN 61557-13 as a current clamp for leakage current measurements.

Logging, alarms and the Fluke Connect wireless link

The 1630-2 FC records readings at a preset interval and stores at least 32,760 values, so a loop can be monitored over a shift or during a switching operation. High and low alarm limits give a quick pass or fail on the spot. The FC in the model name refers to the Fluke Connect wireless system, which sends measurements to an app on a smartphone or tablet; the data sheet warns that the system may not be available in all regions and that some features need a subscription and a mobile data plan, so the instrument is also perfectly usable standalone. Confirm before purchase whether wireless sharing is needed.

Selection and ordering checklist for the 1630-2 FC

• Check that the ground system is a multi-grounded loop; if not, use a stake-based tester.
• Expected loop resistance: accuracy degrades above 100 Ω (3 % + 1 Ω) and is 20 % in the 600 to 1,500 Ω band.
• Conductor or bus bar size against the 40 mm jaw.
• Need for leakage current as well as loop resistance.
• Wireless sharing needs and local availability of the app.
• Calibration certificate and traceability requirement.

Use, safety and maintenance

Centre the conductor in the jaw and keep it perpendicular to the jaw, since the accuracy table assumes loop resistance with no inductance and a centred conductor. Keep the jaw faces clean and fully closed; a gap or a dirty jaw faces causes errors. The instrument is rated up to 1000 V to earth ground and CAT IV 600 V / CAT III 1000 V, but it should still be handled according to the site electrical safety rules, with the correct PPE. Replace batteries with fresh AA alkaline cells before a long logging task and keep the clamp in its case between jobs.

Typical applications in Oman and the GCC

In Oman and the Gulf, stakeless clamps are used for periodic earth checks at substations, petrochemical plants, gas gathering stations, telecom towers and building services, where the ground is often covered with concrete, gravel or asphalt and removing earth links for testing is not accepted by operations. The leakage current function is useful for locating stray currents on earthing conductors in facilities with many variable-speed drives.

Information to send with an RFQ for the 1630-2 FC

• Model: 1630-2 FC (Fluke Connect version) or the non-wireless 1630-2 for comparison
• Earthing system type and expected loop resistance
• Conductor size and access
• Calibration certificate requirement
• Quantity and delivery site

Documents and quotation

The Fluke 1630-2 FC technical data sheet is attached on this page. It includes full accuracy tables for loop resistance and leakage current.

Send the model and the site details and Seven Star LLC will confirm availability and prepare a quotation.