Load Control Features. Liebert 3000, Liebert Challenger 3000, CHALLENGER 3000

System Performance with Advanced Microprocessor Controls

4.4

Load Control Features

4.4.1 Short Cycle Control

The control system monitors the compressor and prevents it from turning on within 3 minutes of being turned off. If this (on, off, on) occurs too often, 10 times in one hour, a Short Cycle alarm could occur.

4.4.2 Sequential Load Activation Control

The control allows only one load output to be energized at a time on a restoration of power or microcontroller reset. Each additional load output will be activated at one second intervals until desired operating conditions have been met.

4.5

Additional Features

4.5.1 Connecting the Analog Sensors

The sensor inputs are factory set to accept a 4 - 20 mA signal. However, the inputs can be changed by removing the appropriate jumpers on the control circuit board. See Table 14, Figure 5 and

Figure 6 .

The user supplied analog sensors MUST have their own power supply. To reduce the effects of interference from any noise source, the sensor input wiring should be shielded twisted pair and the shield tied to earth ground at one end.

Analog input terminals for field connections are factory wired to the microprocessor board if specified when ordered. Eight terminals are located in the field wiring compartment of the unit. Wire sensors to the terminals as follows:

Table 14 Analog input terminals

Terminal

41

42

43

44

45

46

47

48

Signal

Input #1 (+)

Input #1 (–)

Input #2 (+)

Input #2 (–)

Input #3 (+)

Input #3 (–)

Input #4 (+)

Input #4 (–)

Consult your Liebert supplier for a field installation kit to add these connections after unit delivery, if required.

Table 15 Additional connections available after unit delivery

Input #1 Input #2 Input #3 Input #4

4–20 mA

0–5 VDC

Jumper P50.1 & 2 and P50.3 & 4

Jumper P50.1 & 2

0–10 VDC NO Jumper on P50.1 & 2 and P50.3 & 4

Jumper P50.5 & 6 and P50.7 & 8

Jumper P50.5 & 6

NO Jumper on P50.5 & 6 and P50.7 & 8

Jumper P50.9 &10 and P50.11 & 12

Jumper P50.9 & 10

NO Jumper on P50.9 &10 and P50.11 & 12

Jumper P50.13 &14 and P50.15 & 16

Jumper P50.13 & 14

NO Jumper on P50.13 & 14 and P50.15 & 16

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DISCONTINUED

PRODUCT