What is an AMF panel ?

We focus our attention on generator control panels suitable for standby generators.

Navigating through the internet you will find some ‘Frequently Ask Questions’ about a generator control panel (FAQ). The basic keywords are something like these:

  • What is AMF panel ?
  • What size generator to power a house ?
  • How much power does a house use ?
  • How to connect a portable generator to a house ?
  • Connecting Generator to home power.
  • How to use generator to power house ?
  • What is a generator control panel ?

what an AMF Panel is ?

An AMF control panel (Automatic Mains Failure control panel) is the ideal choice in cases where you have to control a generator that is connected to the Mains in a standby configuration.

The AMF control panel is fitted with an AMF controller that manages, in a fully automatic way, the connection assignment of the LOAD to MAINS or GENERATOR avoiding connection MAINS to GENERATOR.  The panel includes miscellaneous equipment:  battery charger, electronic circuit boards,  power relays  and terminal blocks. The AMF  controller is conveniently tasked with driving the power circuit breakers. The size of the circuit breaker capacity and wires defines the required power rating of the panel.

Available sizes on the market are normally in the range 25-500kVA.  A normal house or big villa needs as much as 9kVA of power. This means the following utilities working simultaneously: 1 fridge, 1 air conditioner (or an electric heater), some lights, an oven,  some tools for D.I.Y., 2 computers, 1 TV set an so on. A 10kVA control panel can fit in a plastic that aesthetically complies with your electrical installation.


The AUTO mode is the most interesting part of it. The main AMF controller duty is to continuously monitor the status of the MAINS. The AMF controller allows you to set low/high limits for Mains Voltage and Frequency. You can program limits for the difference of voltage between phases. You can set a preferential phase rotation as well (CW or CCW). Additionally, you can set a limit of power. In other words you can disconnect the load from the MAINS when the request of energy rises above a certain limit.
All these parameters, together with a set of adjustable timers, are compared with the status of the Mains. When the AMF controller fitted into the AMF control panel will find an abnormal situation (for a defined period of time), the AMF control panel will disconnect the load to the Mains. This helps prevent a severe damage to your load. Then, if the failure persists for over the programmed time, the AMF control panel will start the engine of your emergency generator.
The AMF control panel will check the quality of the generator electrical parameters (again here you can set limits on several parameters). Once detected that the parameters are within the allowed limits, the AMF control panel will close the generator circuit breaker. In case of prolonged power outages, your load is safely supplied by your emergency generator and the AMF control panel continuously monitor the system. You can set limits of load or current in order to prevent overloading of your generator. The AMF control panel as mentioned above does not forget to monitor the Mains! So, when the Mains parameters will return within the programmed settings, the AMF control panel will transfer the load to MAINS. This will happen after a delay that will ensure that the Mains is in stable conditions.
Once your load is connected to the Mains, the engine will run for a programmable time (so called COOLING DOWN TIME) without load. After the cooling down time the engine will stop and the AMF control panel is ready for a new power outage.


On the left side a basic wiring diagram of an AMF control panel is provided.


On the removable connector JC you are required to connect the relays. The Bek3 provides a common supply rail (JC8). It is about a dc supply suited for automotive relays that includes over voltage protection, short circuit protection and EMI protection. You are required to use 90-200 OHM dc coil relays (12 V or 24V according to your engine battery).


To a removable connectors JP and JL you will connect the CURRENT TRANSFORMERS suited for the current monitoring of the EARTH FAULT and 3-PHASE GENERATOR. A /5 transformers are required in the range 50 up to 9900Amps. The JA removable plug is used to monitor the Mains & Generator voltage / frequency in the range 80-600V and 20-99HZ. The version BeK3-400Hz is normally available for Aircraft Ground Support equipment.

For a free, no obligation consultation-Helpline No: +91-8287220207 , Email id- info@rkel.in