NuAire NU-99338JE User manual

NuAire Ultra Low Temperature Freezer Service Manual OM0290
OM0290 Revision 2
May/2020 Page 1 of 60 Release Date:5/20/2020
NuAire Ultra Low Temperature Freezer
Service Manual
Model Picture
NU-99338JE/338JG/338JGA
NU-99486JE
NU-99578JE/578JGA/578JGA
NU-99728JE/728JGA/728JGA
NU-99828JE/828JG
NU-99420JE
NU-99420JG

NuAire Ultra Low Temperature Freezer Service Manual OM0290
OM0290 Revision 2
May/2020 Page 2 of 60 Release Date:5/20/2020
1 Contents
1. Contents..................................................................................................................... 2
2. Product Characteristics and Model Meaning ............................................................ 3
3. Product Promotionial Points...................................................................................... 4
4. Product Appearance Structure & Internal Structure Diagram .................................. 5
5.Product Component Structure & Names.................................................................... 6
6. Product Use Introduction & Product Improvement Introduction ........................... 14
7. Main Technical Parameters of the Product ............................................................. 18
8. Case Prevention Measures, Product Use and Daily Maintenance Knowledge....... 21
9. Schematic Diagram and Wiring Diagram of the System ........................................ 26
10. Specific Control, Work Principle and Parameters................................................. 28
11. Refrigeration Cycle Prospective and Plan............................................................. 32
12. Installation & Disassembly Process ...................................................................... 33
13.Typical Troubles & Solutions and Common Q&A................................................ 35
14.Post-maintenancenormal cooling curve data of refrigeration system....................52

NuAire Ultra Low Temperature Freezer Service Manual OM0290
OM0290 Revision 2
May/2020 Page 3 of 60 Release Date:5/20/2020
2 Product Characteristics and Model Meaning
2.1. Main Functions and Characteristics of the Product
2.1.1. The applicable temperature scope in the ultra-low temperature freezer is -40~-86℃;
2.1.2. The freezer has the balanced internal and external pressure design and its doors can be opened
and closed easily;
2.1.3. The display panel is divided into the working area and alarm area to display the machine startup
condition, network connection condition, the voltage increase or decrease and locking condition.
Meanwhile, the high/low temperature alarm and the temperature in the freezer can be set;
2.1.4. The digital display can display the temperature in the freezer, the ambient temperature and the
input voltage, etc. at the same time;
2.1.5. Multiple failure alarms (high/low temperature alarm, sensor alarm, high/low voltage alarm, hot
condenser alarm, improper ambient temperature alarm, door opening alarm, low battery capacity alarm
and power failure alarm);
2.1.6. Two kinds of alarm methods (acoustic silence alarm and light flicker alarm) and multiple protection
functions (start delay protection, low voltage compensation protection and HV compensation protection);
2.1.7. This product has the network function with RS-232 and RD-485 data interface and can be
connected with the computer. The temperature in the freezer is displayed, the alarm information is
displayed via the computer and it is also possible to control the temperature and monitor if the
equipment works properly via the computer;
2.1.8. It has the remote-control alarm function and can connect the alarm device to other rooms to
realize the alarm function;
2.1.9. HV/LV automatic compensation function;
2.1.10. The freezer is equipped with trundles for moving, locking and supporting flexibly and realizes the
micro-adjustment according to the requirement;
2.1.11. The recorder, network monitoring system, message service and stainless-steel rack are
configurable
2.2 Model Meanings
NU 99 578 JE
Energy Savings Model
Effective volume of product
Ultra-low Freezer Designation (ULT)
Nuaire Product designation
Voltage characteristics

NuAire Ultra Low Temperature Freezer Service Manual OM0290
OM0290 Revision 2
May/2020 Page 4 of 60 Release Date:5/20/2020
3. Product Promotional Points
3.1 Temperature Control:
The temperature is controlled by computer and displayed digitally, its adjustment unit is 1℃and the
adaptable temperature scope is -40~-86℃;
3.2 Safety Control:
3.2.1 Multiple failure alarm (high/low temperature alarm, sensor alarm, door opening alarm, hot
condenser alarm, improper ambient temperature alarm, improper voltage alarm, low battery capacity
alarm and power failure alarm);
3.2.2 Two alarm modes (acoustic silence alarm and light flicker alarm) and multiple protection functions
(start delay protection);
3.2.3 All independent components are connected to the ground safely;
3.3 Refrigerating system:
3.3.1 Optimal cascade refrigerating technology, imported compressor and strong refrigerating capacity;
3.3.2 High-density thermal insulation layer, good insulation effect;
3.3.3 Independent multi-layer sealing structure and heat insulation technology, can avoid frosts
effectively;
3.3.4 Special design of low temperature computer control, avoid that the cascade system controls the
low temperature compressor incorrectly;
3.4 Individualized Design:
3.4.1 The LED display panel can display the temperature in the freezer, set temperature, ambient
temperature, input voltage, can set the high /low temperature alarm and the temperature in the freezer
and also has the failure alarm function;
3.4.2 Adjustable rack design for storing and fetching goods easily;
3.4.3 Safety door lock, please avoid opening door casually;
3.4.4 Integrated handle innovation design and compact trundle design, flexible and inconvenient;
3.4.5 Have network function and remote alarm function.;
3.5 VIP
It is made of PU foaming layer + 25mm VIP vacuum insulation material and can reduce the equipment
coverage to the maximum extent;
3.6 Noise
Lower noise, leading in the world comfortable working environment and barely audible for the user.

NuAire Ultra Low Temperature Freezer Service Manual OM0290
OM0290 Revision 2
May/2020 Page 5 of 60 Release Date:5/20/2020
4. Product Appearance Structure & Internal Structure Diagram
4.1 Energy saving series:NU-99486JE NU-99578JE/578JGA/578JGA
NU-99728JE/728JGA/728JGA NU-99828JE/828JG
4.2 Slim line series：NU-99338JE/338JG/338JGA
4.3 Chest series
：
NU-99420JE NU-99420JG
Front View
Internal Structural View
Rear View
Front View
Internal Structural View
Rear View
Front View
Open door View