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A "genset" refers to a backup generator that uses an internal combustion engine. It comprises a generator and a motor. It can come in various shapes, sizes and fuel-supply choices. Small ultra-portable gensets are unsuitable for home-emergency or battery-charging applications. In general, a light generator like this is too small for any home backup use.
Local electrical inspectors and many electrical contractors in North America are still unfamiliar with off-grid systems: it is wise to consult an expert before committing to a system.
Besides the NEC/CEC rules, every electrical appliance requires a Part 2 product standard certification if it operates at either 120V or 240V (AC). If safety is a consideration, this requirement also applies to appliances of lower voltage, such as battery power tools.
Two necessities for safety (and to comply with local and national electrical codes) are to have excess current protection and a means of disconnection on all voltage sources in any ungrounded conductor. This includes all connections between the PV array, batteries, wind turbine and inverter. Almost all AC sources have some form of protection and means of disconnection in any home or appliance wiring. Even the inverter and generator have their own circuit breaker or certified fuse device.
NEC rules state that battery cables cannot be of arc welding wire or other unapproved types: only standard building-grade wires may be installed. CEC allows for all types to be used.
Please check our NEEC Section for further reference.
Wiring batteries in series can up the voltage while a parallel connection can increase the capacity. Battery manufacturers offer a range of voltages and capacity ratings that will meet most requirements. The considerations that are most important in any installation include capacity in amp-hours (Ah), distance from the inverter and voltage. Choosing a battery configuration depends on your required power load and the expected time of operation during blackouts.