Emerson Liebert iCOM User Manual download pdf (Page 26)

Operation

Two Single-Step Compressors Without Unloaders—Two-Step

First single-step compressor, Cool 1, is started at 50% calculated output from the temperature

proportional band, and stopped at 0%. The second compressor, Cool 2, starts at 100% and stops at

50% (see Figure 14).

One Compressor With an Unloader—Two-Step

The two-step compressor is started unloaded at 50%, Cool 1, calculated output from the temperature

proportional band and stopped at 0%. At 100% the compressor starts fully loaded, Cool 2, and returns

to unload operation at 50% (see Figure 14).

Figure 14 Two single-step compressors without unloaders or one compressor with an unloader (two-step)

Two Compressors With Unloaders—Four-Step

The first two-step compressor is started unloaded at 33% calculated output from the temperature

proportional band and stopped at 17%. At 80% Compressor 1 will be loaded, at 70% unloaded.

The second compressor starts unloaded at 63% and stops at 47%. At 100%, Compressor 2 will be

loaded, at 90% unloaded (see Figure 15).

The four stages of cooling are accomplished in the following manner:

• 1 stage: One compressor, unloaded - Cool 1

• 2 stages: Both compressors, unloaded - Cool 2

• 3 stages: One compressor, loaded and one compressor, unloaded - Cool 3

• 4 stages: Both compressors, loaded - Cool 4

Figure 15 Two compressors with unloaders (four-step)

Temp Setpoint: 70°F

Proportional Band: 8°F

Deadband : 2°F

1/2 Proportional Band

Cooling

+ 100%

Cooling

71 72 73 7470

1/2 Dead-

band

Cool 1

Cool 2

Increasing Temperature

Cool 2

Off

Cool 1

Off

Cool 2

Temp Setpoint: 70°F

Proportional Band: 8°F

Deadband: 2°F

½ Dead-

band

Increasing Temperature

½ Proportional Band

757473727170

Cooling

+ 100%

Cooling

Cool 4

Off

Cool 2

Off

Cool 1

Off

Cool 4

Cool 3

Cool 1

Cool 3

Off

1 2 ... 21 22 23 24 25 26 27 28 29 30 31 ... 107 108

Comments to this Manuals

No comments

Emerson Liebert iCOM User Manual Page 26

Comments to this Manuals

Related products and manuals for IP phones Emerson Liebert iCOM