DAE Instrument

The Limit 2/20 is a unique type single phase two wire electronic energy meter, it is different in that it limits the amount of energy consumed per day so as not to exceed a predetermined limit. This meter features a real time clock and control relay, with a built-in CPU that performs the measurement and control. Each meter can be set individually with its own daily limit, once this limit is exceeded then it would automatically cut off the power to the load. The allocation is reset on the next day, the cycle continues thusly.
Limit 2/20 Datasheet (2009/12/24)

There are still many places that lack a reliable source of electricity; hence the need for an alternate source backup power such as a generator in case of a failure in the main power. For most communities, industrial parks or office buildings, the same electricity distribution system is shared by both the city main power as well as the backup generator, with the meter placed at each end user. However, because the cost of electricity is different for city power versus generator power, there is a need to be able to meter each source of power separately so as to fairly charge the cost of electricity. Hence, there is a need for exactly this special type of meter, which has the capability of metering from two different sources of power. Otherwise, one would need two sets of meters as well as two separate power distribution networks for each source of power which would be costly and prohibitive. DAE's dual source meter is a cost effective solution, as one can obviate the need for the duplication of both the distribution network as well as the meters, with just a single meter.