12V 24V 60V Rooftop Electric Refrigerated Unit

The electric refrigeration unit is the core component of the electric refrigerated truck. It is mainly used to maintain the low-temperature environment in the compartment and ensure the freshness or freezing of goods. The following is a detailed introduction to electric refrigeration units:

Product Description

1. Electric refrigeration unit's component:

Evaporator (indoor unit): Responsible for releasing cold air in the cabin and reducing the temperature.

Condenser (outdoor unit): Works in conjunction with the evaporator to remove heat from the cabin through the circulation of refrigerant.

Compressor: It is the power source in the refrigeration cycle. It drives the refrigerant to circulate in the system to achieve the refrigeration effect.

Refrigerant (such as Freon): As a refrigerant, it circulates in the system to complete the process of absorbing and releasing heat.

Copper tube: connects the evaporator and condenser to form a channel for refrigerant circulation.

Thermostat: Used to control the temperature in the cabin to ensure it is within the set range.

2. Electric refrigeration unit’s working principle:

The compressor drives the refrigerant to circulate in the system, and the refrigerant absorbs heat in the evaporator and turns into low-temperature and low-pressure gas.

The low-temperature and low-pressure gas is compressed into high-temperature and high-pressure gas by the compressor, and then enters the condenser.

In the condenser, the high-temperature and high-pressure gas dissipates heat to the outside world and turns into a high-temperature and high-pressure liquid.

The high-temperature and high-pressure liquid passes through the throttling device (such as an expansion valve) and becomes a low-temperature and low-pressure liquid, and then enters the evaporator again to complete the cycle.

Our electric refrigeration unit adapts an independent power source and does not rely on the vehicle's engine. We have 12V, 24V, 48-72V, 110V and 220V types, pure electric refrigeration units, taking power from battery directly.

3. Electric refrigeration unit’s application:

Electric refrigeration units are widely used for transporting fresh vegetables, frozen meat, ice cubes and so on. They can be installed for vans, tricycles, light trucks and so on.

4. Specifications for 12V 24V 60V Rooftop Electric Refrigerated Unit

It's for 1-10 m³ cargo box, transporting fruits, ice, frozen meat or other goods. It adopts DC current from battery, easy to be installed.

Rooftop Electric Refrigeration Unit
Cargo size	1-10 m³
Rated Voltage	12V / 24V / 48-72V / 220V
Electric power	0℃/860W-18℃/460W (Temperature：30℃)
Cooling Capacity	0℃/2650W-18℃/1430W （Temperature：30℃）
Displacement	200CC
Air flow	1200m³/h
Defrost	Automatic / Manual
Package	Wooden box. 736357cm
Gross Weight	54kg

5. Operation manual for rooftop electric refrigeration unit

◎ Controller operation instructions

★ Function Introduction:

·Defrosting: Timed defrosting and defrosting protection

·Temperature Control Range:-50℃~130℃

·Display Range: -50℃~130℃

★ Operation Description:

① Unlocking:Press and hold the "Unlock/Set" button for 3 seconds, until "unlock" light is on, unlocking is successful, and enter the setting parameters.

② Switching parameters: In the unlocked state, press the "Unlock/Set" button to switch between each parameter in sequence.

③ Set Value: In the unlocked state, switch to the desired parameter and use the "+" and "_" keys to adjust the value.

④ Save parameters: Keep no operation for 12 seconds, the display interface will automatically return to the displayed warehouse temperature and lock it. The "unlock" button will turn off, and the parameters will be saved successfully.

⑤ Query parameters: In the locked state, press the "Unlock/Set" button to sequentially query each parameter.

★ Parameter code:

Indicator light	Parameter Description		Range	Factory Default
Start temperature	Set the upper limit of temperature control		-50~130℃	-15℃
Stop temperature	Set the lower limit of temperature control		-50~130℃	-20℃
Compressor delay	Delayed start of compressor: preventing frequent starts		0-600 seconds	6 seconds
Defrosting cycle	Set the time interval between two defrosting cycles		0~600 hours	1 hour
Defrosting time	Set the duration of each defrosting session		0-600 minutes	1 minute
Defrosting stop temperature	Defrosting sensor temperature reaches this value and exits defrosting		1~50℃	25℃
Drip delay	Delayed dripping after defrosting		0-600 minutes	1 minute
C01	Error correction of temperature sensors		-10~10℃	0.0℃
C02	Low temperature alarm: When the temperature below (limit C02),trigger buzzer alarm; “0” means turn off low temperature alarm		0~30℃	0.0℃
C03	High temperature alarm: When the temperature higher than (limit C03),trigger buzzer alarm; “0” means turn off high temperature alarm		0~30℃	0.0℃
C04	Temperature sensor failure(Short circuit or open circuit),enter emergency working mode, work for C04 min, stop for C05 min, .....circulate, C04-0 indicates that the function is turned off		0~600 minutes	0 minutes
C05			1-600 minutes	20 minutes
C06	Compressor running for a long time without stopping alarm: When the refrigeration unit continues to work non-stop If the set value (C06) is exceeded, the buzzer will sound an alarm, and C06=0 indicates that the function is turned off.		0-500 hours	20 hours
H01	Defrosting mode: Electric heating defrosting (When defrosting is triggered, only the defrosting relay is closed; Keep both the refrigeration and fan disconnected) Hot air defrosting (When defrosting is triggered, the defrosting relay and refrigeration relay are both closed)		0=Electric heating defrosting 1=Hot air defrosting	1
H02	Error correction of defrosting sensors		-10~10℃	0.0℃
H03	Defrosting timing method: 0=Temperature controller power on time (Beijing time); 1=Accumulated working time of compressor (Accumulated operating time of refrigeration relay)		0,1	1
H04	Delay time for high temperature alarm after defrosting: After each defrosting, in H04 minutes, no high temperature alarm		0~200 minutes	20 minutes
F01	Fan mode selection: 0=cooling first and then fan; 1=Fan first, then cooling; 2=Fan keep running (When F01=2, the fan keep running, and only disconnect during defrosting or delayed dripping)		0,1,2	0
F02	Cooling and fan start time (Staggered start, only effective at F01=0 and F01=1)		0~999 seconds	20 seconds
F03	Fan delayed shutdown (Only effective at F01=0 and F01=1)		0~999 seconds	0 seconds
F04	After stop cooling, the fan operates periodically for a period of time	When the temperature sensor reaches the shutdown temp, the refrigeration relay disconnect, After timing the F03 parameter, the fan relay opens with a delay. Then, the fan relay enters a cyclic working state, with F05 minutes of disconnection, F04 minutes of closure, F05 minutes of disconnection, and F04 minutes of closure. This cycle continues until the temperature sensor reaches the startup temperature again. Only valid at F01=0 and F01=1.	0~9999 minutes	0 minutes
F05			0~9999 minutes	0 minutes

★ Screen display and operation:

When in standby or cooling mode: the upper screen displays the refrigeration unit temperature, the lower screen displays the shutdown temperature, and click the "Manual defrosting/Stop defrosting" button, the upper screen displays the temperature of the defrost sensor, and the lower screen turns off.

When defrosting: the upper screen displays the defrosting sensor temperature, and the lower screen displays the remaining defrosting time. (Minutes)

★ Rapid cooling:

After powering on, press and hold the "strong cooling" button for 3 seconds, it can directly enter the cooling start.

★ Defrosting instructions:

·Manual defrosting: Keep pressing “Manual defrosting/Stop defrosting" button, Entering (or exiting)

·Starting conditions for defrosting:① The defrosting cycle setting value is not 0;② The temp of the defrosting sensor is lower than the set value of the stop defrosting temp; ③ Reach to the defrosting cycle setting time.

·The conditions for the end of defrosting:① Set the defrosting cycle to 0; ② The defrosting operation time has ended; ③ The defrosting temp is higher than the set value of the stop defrosting temp; ④ Manually stop defrosting;

★ Fault code description:

How to use the "Cancel Alarm" button: When an alarm occurs, the buzzer will sound. Keep pressing the "Cancel Alarm" button to stop the buzzing.

Code	Alarm Description	Controller shows
E1	Temperature sensor malfunction（short circuit or open circuit)	The controller enters emergency working mode (C04 C05), buzzer alarm.
E2	Defrost sensor malfunction（short circuit or open circuit)	All relays are working properly, and the buzzer alarms.
E3	Ultra high temperature alarm	All relays are working properly, and the buzzer alarms. (Set C03 to 0, turn off it)
E4	Ultra low temperature alarm	All relays are working normally, buzzer alarm, and refrigeration relay stops working. (Set C02 to 0, turn off it)
E5	The refrigeration unit keep working without shutdown	All relays are working properly, and the buzzer alarms. (Set C06 to 0,turn off it)

Installation steps and precautions

=> Rooftop model

Cut a properly hole on the roof, it should be 32*50CM

Let the evaporator through into the hole

Seal the 4 sides of the hole with polyurethane foam adhesive

Connect the power line to the battery

=> Split model

Fix the components

Install and fix the external unit assembly, evaporator assembly, and controller assembly on the vehicle body in sequence.

Pay attention during installation:

The external unit should be installed horizontally to avoid tilting and causing operational damage. The screws installed on the support feet must be firmly fixed.

The evaporator assembly is fixed in a position with good air circulation, try not to have any obstructions at the rear of the intake grille and electronic fan, avoid insufficient ventilation leading to reduced cooling efficiency;

When installing the evaporator assembly, pay attention to the position of the water outlet and do not install it in the opposite direction.

Maintain a certain tilt angle of the evaporator box during installation, so that the water outlet position is lower.

The controller is a general waterproof component and should be installed in a ventilated and waterproof location.

Connect the pipes

There are three high- and low-pressure pipelines, with diameters ranging from thin to thick, namely 3", 4", and 5". The pipes are equipped with pipe joints and O-rings when they leave the factory. Check whether the pipe joint is deformed and whether each O-ring is damaged. If there are any abnormalities, replace them with new ones.

Carefully remove the sealing protective components at the interface in sequence, and connect the corresponding interfaces according to the markings.

Vacuum and fill refrigerant

After checking that all connections are undamaged and the pipeline connections are intact, connect the high-pressure end of the dual pressure gauge to the 3’interface of the main machine, low-pressure connect to 5’,connect the yellow pipe of the dual pressure gauge to the exhaust end of the vacuum pump, and simultaneously open the high and low pressure valves to the maximum；

Turn on the vacuum pump to pressurize to 12-15MP, close the high- and low-pressure valves, and then turn off the vacuum pump;

Observe and record the pressure gauge scale. If there is no change in the pressure scale after half an hour, it indicates that the system is well sealed.

If the pressure decreases, carefully check the system leakage point, and repeat the above operation after repair until there is no leakage in the system.

⑤ After completing all steps above, remove air from the refrigeration unit (slowly release, do not open it all at once),connect the yellow pipe of the dual pressure gauge to the suction pipe of the vacuum pump, and open the high and low pressure valves to the maximum. Continuously pump for about 15 minutes until no gas is released from the outlet nozzle. Close the high- and low-pressure valves and turn off the vacuum pump.

⑥ Open the low-pressure and high-pressure fluorine locking valves in sequence, and then start the machine to run.

Attention: Do not power on the refrigeration unit in vacuum state.

If refrigerant leaks, 1kg ± 5% R22A refrigerant can be added to the unit according to its actual situation. When do the Freon filling, it must be done from low pressure connector, starting from evacuate the air in the yellow tube, otherwise cooling performance will be affected.