Issue: 01.05.2019
Page 9
Commissioning
High pressure safety
The high pressure safety switch is required to stop the compressor
should the discharge pressure exceed the values shown in the
following table. The high pressure switch can be set to lower values
depending on the application and ambient conditions.
Low pressure safety
The low pressure safety switch protects the compressor against
deep vacuum operation, a potential cause of failure due to internal
arcing and also operation outside the compressor limits.
The low pressure safety cut out should never be set below the
settings as shown in the following table. For systems without pump-
down the LP switch signal contact shall be used to energize a low
pressure safety alarm.
Compressor operating pressures
Compressor operating pressures should be kept within the
following limits:
Recommended compressor working pressure range
XGE Fan Speed Controller (Series 2 & 3 & 4 Units)
The fan speed controller is factory set to 19 bar for operation with
R4*** series refrigerant to ensure compressor always operates
within envelope at all declared working condition. If operate with
R134a, the fan speed controller setting need to be set to 13bar.
This can be adjusted to suit site conditions / application or
alternative refrigerants. The XGE controls are set to stop fan at
Pmin.
Recommended settings to gain higher energy efficiency as
published in the Ecodesign data sheets are as follows:
Medium Temperature
Low Temperature
Fan control Switch (Series 1 LT units only)
The high energy efficiency as shown in eco-design sheet can be
obtained with the setting shown in below table.
For model in Series 1 LT:
Discharge Thermostat
Model JEHS-0750-B4-L-3 and all EVI units are mounted with
discharge thermostat (cut off = 125⁰C, cut in = 90⁰C) to protect the
compressor. For other unit models, it is recommended to install
the discharge thermostat if operating in extreme condition (low
evaporating and high ambient temperature).
Compressor
Refrigerant
S1/S2
Max. HP Set
Compressor
MTZ
NTZ
MTZ
Refrigerant R404A/R407A/R407F/R448A/R449A/R452A R404A/R452A
R134a
S2
Max. HP Set
18 bar
Compressor
ZB
Refrigerant
R134a
S2/S3/S4 Max. HP Set
18 bar
27 bar
27 bar
Unit Series
ZB/ZF/ZFI
R404A/R407A/R407F/R448A/R449A
AE/CAJ/TAJ
R404A/R407A/R407F/R448A/R449A/R452A
27 bar
Unit Series
Unit Series
Compressor Model
CAJ/NTZ ZF/ZFI
Unit Series
1&2
2 & 3 & 4
R404A
R404A
R404A
R404A
R407A
R407A
R448A
R407A
R407F
R407F
R449A
R407F
R448A
R448A
R452A
R448A
R449A
R449A
R449A
R452A
Application
M in. Cut Out (barG)
1
0.6
2
0.6
0.1
0.3
M in. Cut Out (psi)
15
9
30
9
2
5
R449A
R452A
1.5
22
L*
AE/CAJ/TAJ
MTZ
ZB
1 & 2
2
2 & 3 & 4
Refrigerant
R134a
R134a
M*
R404A
R407A
R407F
R448A
Compressor Model
CAJ/NTZ ZF/ZFI
Unit Series
1&2
2 & 3 & 4
R404A
R134a R404A R134a
R404A
R404A
R407A
R407A
R448A
R407A
R407F
R407F
R449A
R407F
R448A
R448A
R452A
R448A
R449A
R449A
R449A
R452A
Application
M * M edium Temperature
L* Low Temperature
0.1 ~ 3.3
13.2 ~
27.7
13.2 ~
27.7
2.0 ~
7.1
0.6 ~
3.8
0.1 ~ 3.3
13.2 ~ 27.7
1.5 ~ 8.3
Low Side (barG)
1.0 ~
7.2
0.6 ~
4.7
Refrigerant
M*
R404A
R407A
R407F
R448A
R449A
R452A
L*
High Side (barG)
13.2 ~
27.7
7.9 ~
15.8
7.1 ~
27.7
6.6 ~
15.8
AE/CAJ/TAJ
MTZ
ZB
1 & 2
2
2 &3 & 4
Refrigerant
R134a
Series 2
19
13
Series 3
10
13
Series 4
10
10
Setting
R404A/R407A/R407F/R448A/R449A/R452A
Refrigerant
19
13
17
R404A/R407A/R407F/R448A/R449A/R452A
JEHR Models - Series 2
JEHS Models - Series 2 & 3 & 4 (except EVI)
JEHS Models - EVI unit
Setting
Refrigerant
R404A
R448A
R449A
R452A
Setting (bar)
Cut in
Setting (bar)
Differential
* default factory setting
16*
7*
Clockwise: Increase
pressure set point
Anticlockwise: Decrease
pressure set point
360
0
= 1 turn
Approx. 1.5 barG
