CURB - Conserving CT clamps during Installation
When an installer does not have enough CT clamps to monitor every breaker in a panel, there are three options to consider that will allow more breakers' circuits to be monitored: 1) Combining multiple breaker's circuit wires into a single CT clamp; 2) Conserving CT clamps on double and triple pole breakers by applying the multiplier in the software; and 3) Using the “Other” category for unmonitored circuits within the software.
Combining multiple breaker's circuit wires into a single CT clamp.
Remember that the total of the breakers' amperage should not exceed the amperage of the CT clamp and the breakers need to be on the same phase. If a house has two 15A breakers for an office (one for plugs and one for lights), you can combine those two circuits into one CT and label it "Office Total". If these were both 20A breakers, this would exceed the capacity of a 30A CT clamp and not be recommended because it may affect accuracy. Use the max load of the combined breakers to determine which CT size to use.
Using the "Multiplier" within the configuration software.
This option can be reserved for double-pole and triple-pole breakers. This means using one CT clamp on one phase (e.g. one half of the breaker pair). The lack of monitoring both sides of the dual phase circuit is adjusted for in the software, by choosing the multiplier for a “Double Pole” or a “Triple Pole” breaker.
This setting should be adjusted during installation by the electrician, however this can be changed after the fact. The account holder can confirm this setting by going to the installation side of the web app.
The use of this setting is accurate only if there are balanced-load appliances (such as a furnace or water heater) on the circuit. Some appliances (like electric dryers) will use a substantial amount from only one leg (to run the motor in the dryer). As a result, the application may provide either more or less of an accurate reading if place on an unbalanced load.
Using the “Other” category for unmonitored circuits.
In the case where there are not enough CT clamps to monitor each breaker and circuit, you can use the software to group them into the “Other” category. This will allow the account holder to view usage for the total unmeasured circuits in a home. It is calculated by subtracting the sum of all measured circuits from the total consumption on the mains. The idea here is that you have limited “Other” to the breakers that use the least power. If the “Other” category is higher than 10%, this is probably an indication of an incorrect placement of CT clamps, requiring some reworking or reordering.
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