Emerson AE4-1395 Manuel D’Utilisation

6

© 2012 Emerson Climate Technologies, Inc.

Printed in the U.S.A.

Application Engineering

B

U

L

L

E

T

I

N

bar) for R-407C & R-22 to prevent evaporator coil icing. 

The cut in setting can be as high as 180 psig (12.5 bar) 

for R-410A and 105 psig (7.2 bar) for R-407C & R-22 to 

prevent rapid recycling in case of refrigerant loss. 
For heat pumps, a cut out setting no lower than 20 psig 

(1.4 bar) is recommended for R-410A and 10 psig (0.7 

bar) for R-407C & R-22.

Scroll Temperature Protection
Most digital scrolls do not have internal discharge 

gas temperature protection. In order for the Emerson 

controllers  to operate properly an NTC sensor must be 

attached to the compressor discharge line as close as 

possible to the compressor discharge fitting. For best

response the sensor should be insulated. See 

Table 1 

of 

AE8-1328 for thermistor temperature vs. resistance 

values. Refer to 

Table 4 for part numbers of discharge 

line thermistors. 

Figure 7 illustrates the two different 

types of discharge thermistors.

The ZRD61 through ZRD81KC compressors have a 

discharge thermistor that is inside of a well in the top 

cap of the compressor.  If this thermistor ever needs to 

be replaced, it should be replaced with either 985-0199-

00 or 085-0204-00 as listed in 

Table 4.

Crankcase Heaters
A crankcase heater is required if the system charge 

exceeds the system charge limits listed in 

Table 2.  

For more information regarding regarding heater part 

numbers and installation location please refer to the 

equivalent non-digital scroll Application Engineering 

bulletin listed on 

Page 4.

Oil Type and Oil Removal
Mineral oil is used in the ZRD*KC compressors for 

R-22 applications. Polyolester (POE) oil is used in 

the ZRD*KCE and ZPD*KCE compressors for R-22 

& R-407C and R-410A applications respectively. See 

the compressor nameplate for the original oil charge. A 

complete recharge should be approximately four fluid

ounces (118 ml) less than the nameplate.

It is an approved practice to use ZRD*KCE compressors 

with POE to replace ZRD*KC compressors with mineral 

oil in R-22 service applications.  R-22 has been approved 

for use with both mineral and POE and some mixing of 

these oil in the system is acceptable.

If additional oil is needed in the field for POE 

applications, Copeland

™

 Ultra 32-3MAF, Lubrizol 

Emkarate RL32-3MAF, Parker Emkarate RL32-3MAF/

Virginia LE32-3MAF, or Nu Calgon 4314-66 (Emkarate 

RL32-3MAF) should be used. Copeland Ultra 22 CC, 

Hatcol EAL 22CC, and Mobil EAL Arctic 22 CC are 

acceptable alternatives.

If  additional  oil  is  needed  in  the  field  for  mineral  oil

applications, Sonneborn Suniso 3GS or Chevron 

Texaco Capella WF32 should be used.

and polycarbonate).
Power Factor
During the loaded state the digital scroll compressor 

operates at full capacity and the power factor is the 

same as a standard scroll. However, when the scrolls are 

unloaded, the power factor is much lower. If power factor 

is an important consideration, the correcting capacitors 

should be calculated using the full capacity data to avoid 

problems associated with over correction. See 

AE9-1249 

for more information on power factor correction.

Tandem Applications
Tandem compressors follow the same application 

guidelines as single compressors outlined in this bulletin. 

The refrigerant charge limit for tandem compressors is 

shown in 

Table 2. A tandem circuit with a charge over 

this limit must have crankcase heaters applied to both 

compressors.

Tandem compressor assemblies are available for 

purchase from Emerson. In lieu of purchasing the 

assembled tandem, the OEM has the option to 

purchase the tandem-ready compressors to assemble 

the  compressors  into  a  tandem  configuration  in  their

manufacturing plant.  Drawings of the tandem manifolds 

are available by contacting your application engineer. 

Figure 9 illustrates a typical tandem compressor 

assembly using 3 through 7.5 ton scroll compressors.  

Note that only one compressor in the tandem assembly 

is a digital scroll compressor. 

For more information on tandems, please refer to the 

non-modulating compressor Application Engineering 

bulletins listed on 

Page 4.