What must all three-phase self-contained meter installations be equipped with for safe meter reading?

Three-phase self-contained meter installations require test blocks to facilitate safe and accurate meter readings. Test blocks are essential components that allow for convenient and secure access to the circuit without needing to disconnect the meter or interrupt service. This setup ensures that technicians can perform tests safely, with appropriate protective measures in place, minimizing the risk of electrical hazards while maintaining accuracy in readings.

Test blocks typically provide a way to isolate the meter from the load or power source, allowing technicians to measure voltage and current safely. This is particularly important in a three-phase system, where the complexity of the connections can pose increased risks during maintenance or testing.

In contrast, while safety valves, warning lights, and remote access systems serve various purposes in electrical installations, they do not specifically address the safety and accessibility needs for reading three-phase self-contained meters. Safety valves may relate to pressure systems, warning lights could indicate general maintenance conditions, and remote access systems enhance monitoring but do not directly facilitate safe meter reading like test blocks do.