The PRIORITIZER® from SEQUENT Power

Operation

This is an example for a typical household, with an electric 240v water heater which, due to its high energy usage, would normally require a larger capacity generator to be installed in order to operate the water heater along with the remainder of the loads. If we can wire the water heater to only be able to run when the other loads are off, we can handle the load requirements with a smaller backup system. For this example, we will use an ECS 4200 unit.

Here we are wiring four 120 volt loads (Refrigerator, Sump Pump, Freezer, Well Pump) to the four P1 channels, and the 240 volt water heater (both wires) to the P2 channel.

When power is restored, voltage is supplied to all loads simultaneously. Current (amps) then begins to flow to all loads which are on. The PRIORITIZER senses that one of the P1 loads is drawing current and then turns off the P2 loads. This arbitration occurs within 16-33 mSec., preventing P2 loads from actually starting.

After the well pump runs long enough to pressurize the bladder tank, and turns off, the PRIORITIZER senses that the refrigerator and/or freezer P1 loads are still drawing current and keeps off the P2 loads.

The refrigerator runs for one hour to cool enough to turn itself off. The PRIORITIZER senses that the freezer P1 load is still drawing current and keeps off the P2 load.

The freezer needs to run for about one more hour to cool down but the well pump comes on after the freezer has been running for 15 minutes. Since in this example the freezer and the well pump are both P1 loads, they are both allowed to run at the same time. The well pump runs for 4 minutes, and shuts off. The freezer continues to run for 45 minutes to finish itsí cool down cycle.

At this point, none of the P1 loads is operating. The PRIORITIZER now applies voltage to the water heater P2 load (240v) which will continue to draw current and heat until 1) it reaches setpoint temperature or 2) a higher priority load ( possibly the Sump Pump ) turns on.

If the total duty cycle of all loads averages less than 100%, the system will reach equilibrium and all loads will maintain their set pressures, temperatures, etc.

After a while, the operation of all loads will return to random operation, with the PRIORITIZER inhibiting loads only occasionally and all loads operating within their setpoints. If the combined duty cycle is 70%, this will happen much faster than if it is 90%. If the combined duty cycle is over 100%, the lowest priority load (water heater) will never reach itsí turn off setpoint.

In this case, it would only be an inconvenience if the water heater did not get hot enough.

But if the freezer or refrigerator were the P2 loads, then the safety of food preservation may be at risk. Therefore, the duty cycle sum of these type of loads should never exceed 100% by themselves. If the sum of the duty cycles food refrigeration/freezer loads add up to close to 100%, then they should be divided among several units with other low duty cycle loads. If you are concerned about the possibility of food spoilage due to the malfunction of the PRIORITIZER or of one of the other appliances never shutting off, DO NOT wire any food preservation units on a priority lower than Priority Number one.

Other PRIORITIZER models will wire and operate in a similar fashion. Simply replace the number of priority levels and the number of lines per priority into the above scenario to understand the operation.