Catalog No. 300 - Hot Socket Gap Indicator

Hot Socket Gap Indicator
Red Indication of a “bad” socket gap/loss of spring force
No indication of a “bad” socket gap/loss of spring force

The TESCO Hot Socket Gap Indicator (Catalog No. 300) is quick, easy-to-use and has a rugged, non-conductive insulated shell. The mechanical tool engages the jaws of a meter socket and will indicate a gap or significant loss of jaw pre-load. Total estimated time of testing four jaws is less than 30 seconds. Even minor gaps can result in electrical arcing, resulting with a more serious problem, failure, or electrical fire.

The TESCO Cat. 300 will work with all sockets, including meter socket jaws with designed-in gaps, and socket jaws which have fresh lubricant.

Note: If feasible, service should be disconnected. Regardless of whether the service has been disconnected or is live, personal protective equipment (PPE) should always be used while operating.

See frequently asked questions about the Hot Socket Gap Indicator.


  • Easy-to-use design
  • Determines unsafe holding-force on meter socket jaws based on laboratory testing
  • Blade spring force was designed to effectively determine a minimum unsafe threshold
  • Insulated plastic body (Rated 3000 V)
  • Tin-plated spring steel blade used to withstand daily use, travel, and vibration
  • No maintenance required
  • Calibrated for 5 years or 1,000,000 sockets (whichever occurs first)
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