Can an electric energy meter with load control function replace an air switch

When smart meters are equipped with load control functions and can remotely cut off power, many users have a tempting idea: can this "smart meter" directly replace traditional air switches (circuit breakers) and achieve a "simplified revolution" in distribution boxes? Behind this seemingly reasonable idea lies a significant cognitive misconception regarding household electrical safety. This article will delve into the essential differences between the two and uncover the core reasons why smart meters cannot replace air switches.

1、 Mission Gap: Intelligent Butler vs. Security Guard (Fundamental Positioning Difference)
The core mission of smart energy meters:
Precision perception and strategic control are its soul. The essence of the load control function of smart meters is policy based active management, such as responding to grid peak shaving and valley filling instructions, executing user preset electricity plans (such as timed shutdown of water heaters), or automatically switching devices based on electricity pricing strategies. It is more like an 'energy steward', managing the economy and planning of electricity consumption.
The core mission of air switch:
Life safety and equipment protection are its unshakable cornerstones. It is the last passive defense barrier in electrical circuits, designed to respond to fatal faults within milliseconds:
Short circuit protection (Magnetic Trip): When a phase to phase/phase to zero short circuit occurs (current instantly surges to thousands of amperes), the electromagnetic trip mechanism forcibly disconnects the circuit within<0.1 seconds to avoid wire melting and fire.
Overload protection (Thermal Trip): When the circuit is continuously overloaded (such as using a socket for overload), the bimetallic strip will bend due to heat and act within seconds to minutes to prevent insulation aging, overheating, and fire.
Leakage protection (RCD/GFCI): Specialized leakage circuit breakers can trip within<0.03 seconds in the event of human electric shock or line leakage (current difference ≥ 30mA), saving lives.
Electric energy meters are the "smart brain" responsible for optimizing operations; The air switch is an 'instinctive muscle' responsible for protecting life. There is a fundamental gap in their responsibilities.

2、 Performance gap: Fast, accurate and ruthless physical defense vs logical judgment (difference in technical capabilities)
Intelligent energy meter air switch (circuit breaker) with load control capability dimension
Response speed from seconds to minutes (dependent on communication and processing logic) to milliseconds (purely electromagnetic/mechanical action, no communication required)
Protecting the stability of the power grid, the economic and personal safety of users, and the physical safety of power lines and equipment
Key protection types: Overpower cut-off (based on set threshold), short circuit, overload, leakage (physical fault response)
Action mechanism: Remote signal driven internal relay, electromagnetic force driven mechanical trip (physically forced disconnection)
Reliability relies on communication networks, software logic, and stable power supply with pure mechanical/electromagnetic structures (fault self assurance)
Standard certification for energy metering standards (such as IEC 62053) and circuit protection standards (such as IEC 60898)
Deadly gap: Lack of short-circuit protection capability
The load control relay inside the electric energy meter (usually a small relay or solid-state relay) does not have the ability to break thousands of amperes of short-circuit current. When a real short circuit occurs, the relay contacts will completely fail due to the huge arc melting and adhesion, making it impossible to disconnect the faulty circuit. Only the dedicated arc extinguishing device of the air switch can safely break the short-circuit current.
Insufficient accuracy and speed of overload protection
The power cut-off of the electric energy meter is based on software set threshold and calculation, and the response speed is much slower than the bimetallic thermal protection mechanism of the air switch. In continuous overload scenarios, the risk of line overheating significantly increases.
No leakage protection function
The vast majority of smart energy meters do not include a functional module for detecting leakage (residual current), and have no defense against the risk of personal electric shock.
3、 Regulatory red line: Mandatory certification and installation specifications (compliance differences)
National mandatory certification barriers:
Air switches (circuit breakers) belong to CCC mandatory certification products and must pass strict type tests (including breaking capacity, lifespan, temperature rise, etc.) to ensure that their protective performance meets the standards. Although smart energy meters also require metrological certification, their load control modules have never been certified as circuit protection devices.
The electrical installation standards explicitly prohibit:
National standards such as GB51348 for electrical design of civil buildings clearly stipulate that:
Distribution lines should be equipped with short-circuit protection and overload protection devices (such as air switches).
The residual current action protector (leakage switch) should be installed at the front end of the load side.
The electric energy meter and its load control function are not included in any legal protection device category.
Clear responsibility boundaries:
The property rights of electric energy meters usually belong to the power supply company, and their load control function is mainly used for remote cost control (power outage due to arrears) or to cooperate with demand response. The air switch is a safety barrier on the user's property rights side, and the responsible party is clear. Mixing will result in a vacuum of safety responsibility.

4、 Dangerous scenario: Failed 'intelligence' and real disasters
Imagine a typical household scenario: a user replaces the air switch in the kitchen circuit with a smart meter.
Scenario 1: Short circuit disaster (the  dangerous!)
The old kitchen socket has an internal short circuit, instantly generating a fault current of 8000A.
The outcome of the electric energy meter: The internal load control relay contacts are continuously conducting due to the huge arc welding.
There should be protection: the air switch should trip within 0.02 seconds.
Consequence: The wire continues to overheat, causing the insulation layer to catch fire and trigger a fire.
Scenario 2: Overload hazard
In winter, multiple high-power heaters are turned on simultaneously, and the circuit continues to operate at 1.5 times overload.
The outcome of the energy meter: It may be cut off after a few minutes or even longer (reaching the power threshold or communication delay).
There should be protection: The bimetallic strip of the air switch will overheat, bend, and trip within a few minutes.
Consequence: Accelerated aging of circuit insulation may  to electrical fires in the long term.
Scenario 3: Risk of Electric Shock
The electric water heater has internal leakage and the shell is electrified.
The result of the electric energy meter is that it is completely unable to detect leakage and will not operate.
There should be protection: the leakage switch trips within 0.03 seconds.
Consequence: The user may come into contact with the casing of the water heater, suffer electric shock, and endanger their life.
5、 Correct direction: Integration and symbiosis, not substitution (intelligent upgrade solution)
The true intelligentization of household electricity should pursue the collaborative evolution of protection and control, rather than functional substitution. The synergy of "smart energy meter+smart air switch" should be:
Retain the energy meter for overall metering and strategic control, while installing miniature circuit breakers (MCBs) or intelligent leakage protection with communication functions in each circuit. The electric energy meter can send instructions to the intelligent air switch (such as "cutting off the kitchen circuit if it exceeds 3000W"), but the protection function is still independently completed by the intelligent air switch. This solution balances security and intelligence.
Load control as a supplementary means:
The load control function of an electric energy meter can be used in non critical and non high-risk scenarios, such as:
When the total power approaches the upper limit, the electricity meter remotely cuts off interruptible loads such as pool heaters and electric vehicle charging stations.
Cooperate with demand response and temporarily shut down non essential equipment.
Core principle: Any cutting operation involving personal safety and line protection must be carried out by a circuit breaker or leakage protector that meets the standards!

Intelligent energy meters with load control functions are important tools for refined energy management, but they should never and should not be the guardians of household electrical safety. The millisecond level physical tripping ability, thousands of amperes breaking strength, and reliability verified for over a hundred years of air switches (circuit breakers) are the last line of defense for protecting life and property, and cannot be replaced by software logic and ordinary relays.
The true smart use of electricity is to enable professional equipment to perform their respective duties: to enable energy meters to focus on "perception" and "strategy", to enable air switches to adhere to "protection" and "defense", and to achieve seamless collaboration between the two through intelligent technology. Any attempt to cross the safety red line in the name of 'intelligence' is a departure from the ethics of science and engineering, and may ultimately incur irreparable costs. Choosing compliant protective devices is the  fundamental commitment to family and the true cornerstone for the safe operation of smart homes.