AMX Power Current Sensors PCS - Manual (Page 11)

Calibration
7 PCS and PCS2 Power Current Sensors
Calibration
The PCS and PCS2 work by setting a threshold. The STANDBY threshold is set be-tween the
current draw of the OFF state and that of the STANDBY state. The ON threshold is then set
between the current draw of the STANDBY state and the ON state.
The PCS2 contains two major circuits, each independent of each other. Each if these major circuits
contain two sub-circuits, the ON and STANDBY circuits. The following paragraphs will address
the sub-circuits for each major circuit of the PCS2.
PCS
The state status for the PCS is:
! STANDBY senses when the current is at or below standby threshold. The LED lights and
relay switch output is closed when below ON.
! ON senses when current is at or above ON threshold. The LED lights and relay switch
output is closed when above ON.
! The circuit (both the ON and STANDBY) can differentiate between 20 mA and 1 A.
Anything above 1 A is sensed as 1 A, regardless if it is 2 A, 6 A, or 10 A.
PCS2
The PCS2 has an inline 10 A fuse for protection. This will allow one, or both major circuits to draw
a maximum of 10 A (1,200 W) total.
The state status for each of the major circuits of the PCS2 is:
! STANDBY is lit when the sensed current level is above STANDBY threshold.
! STANDBY remains lit (regardless of its setting) when the ON LED lights.
! ON is lit when current is above the ON threshold.
! The circuit (both the ON and STANDBY) can differentiate between 20 mA and 1 A.
Anything above 1 A is sensed as 1 A, regardless if it is 2 A, 6 A, or 10 A.
! It is not logical for ON to light before STANDBY. As a result, the circuit is de-signed so
that if the ON is lit, the STANDBY will also be lit, regardless of its setting.
When extreme accuracy is required for calibration, it is best to plug the PCS or PCS2 into a wall
outlet at least 15 minutes before calibration to allow the circuitry to warm up. Calibration of the
PCS and PCS2 must be accomplished prior to use. Calibration of the PCS and PCS2 is
accomplished as follows:
PCS Calibration
In the PCS, the ON state is dependent of the STANDBY mode but the STANDBY mode is not
dependent on the ON mode. They work together to provide a final level, where the Standby power
level provides a base and the ON level is an increment to that level. FIG. 7 illustrates the
relationship that the STANDBY and ON power levels have with each other in determining the final
power level.