KL3228 - Positioning within the Bus Terminal Block

Connect the back wires of the eight PT sensors via a potential distribution terminal (KL9187). The KL9187 leads the back wires via Power Contact (0 V) back to the KL3228.

Mount the KL3228/KL9187 directly before the KL9010 bus end terminal

Mount the KL3228/KL9187 directly adjacent to each other and as far to the right as possible in the Bus Terminal block, ideally directly before the KL9010 bus end terminal!
If further Bus Terminals that draw current from the power contacts are mounted to the right of the KL3228/KL9187 in the Bus Terminal block, this current will lead to a voltage drop on the power contacts between KL3228 and KL9187. This voltage drop can falsify the measured values of the KL3228, since the back wires of the PT sensors are also routed via the power contact (0 V).

Example for bad positioning

This example shows the KL3228/KL9187 mounted on the left in the Bus Terminal Block. There are big current consumers mounted to the right side of KL3228/KL9187.

KL3228 - Positioning within the Bus Terminal Block 1:
KL3228/KL9187 - Example for bad positioning

The KL2442 drives a current of 4 A through each of the two load resistors R1 and R2.
This current (8 A in total) must flow back to the power supply unit via the power contacts
and causes the voltage drop UPC on the power contact marked in yellow (between KL3228 and KL9187).

The KL3228 drives a current through the sensor S1.
This current similarly flows back to the KL3228 via the power contact marked in yellow.
The voltage drop UPC thus causes a measuring error during the resistance measurement by the KL3228.

Example for good positioning

This example shows the KL3228/KL9187 mounted on the right in the Bus Terminal Block. No further current consumers are mounted to the right of KL3228/KL9187.

KL3228 - Positioning within the Bus Terminal Block 2:
KL3228/KL9187 - Example for good positioning

The current from the load resistors R1 and R2 does not flow back via the power contact marked in yellow (between KL3228 and KL9187).
The voltage drop UPC at this power contact can thus be neglected.
No additional measuring error occurs during the resistance measurement by the KL3228.