System information

ManualsBrandsEmerson ManualsKitchen AppliancesAE4-1287 R7

AE4-1287 R8

Figure 1 – Demand Cooling System

nomenclature beginning with -ADx (e.g. 4DKNF63KL-

TSK-AD0) Demand Cooling capability is built in.

4D and 6D Unloading with Demand Cooling

Demand Cooling protection is applicable with

compressors using conventional blocked suction

unloading. Earlier application guidelines required

that liquid injection only occur when the compressor

is in its fully loaded state. This was to avoid ﬂ ooding

the compressor with saturated liquid. After further

evaluation, Emerson engineering has determined

that the Copeland Discus compressor will still ﬂ ash

the injected liquid refrigerant when the compressor is

unloaded should the discharge temperatures govern

the need for added cooling. The Demand Cooling

module will only inject liquid when required. When the

temperature decreases to an acceptable level, the

module will stop injecting.

3D Copeland Discus Digital with Demand Cooling

Demand Cooling can be used with 3D Copeland

Discus Digital compressors without adding extra

unloader control circuitry. The Demand Cooling

temperature sensing probe must be installed to replace

the temperature sensing probe that is provided with

the Digital Compressor Controller (IDCM). The T1 to

T2 connection on the Digital Compressor Controller

should be jumpered with a 5 kOhm 1 Watt resistor.

This allows the Demand Cooling module to protect

against high discharge temperatures and inject liquid

when needed.

Performance Adjustment Factors

Performance values for R-407A, R-407C, R-407F,

R-448A and R-449A are not provided in this bulletin. For

actual performance values refer to Product Selection

Software (PSS) or the Online Product Information (OPI)

at EmersonClimate.com.

Since compressor discharge temperature depends

strongly on the return gas temperature, the amount

of injection and its effect on evaporator capacity and

mass flow will vary somewhat with return gas

temperature. The approximate effects of compressor

return gas temperature on evaporator capacity and

mass ﬂ ow are calculated in the current version of

Copeland Product Selection Software (PSS).

Demand Cooling Speciﬁ cations

Demand Cooling is designed to operate and

protect the compressor within the evaporating and

condensing envelope identiﬁ ed in Figure 2. Operating

setpoints and control actions are listed in Table 1.

Attached is the Demand Cooling Diagnostic

Troubleshooting Guide (Form No. 92-91)