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Mono-block unit Instrution Manual

  Type:Company News   Date:2017-09-05 15:00:26  
How to use mono-block unit?
Instruction Manual
for ChinaTechco Cold/Freezer rooms only
TECHCO Refrigeration Solution 
Taizhou Chengshun Refrigeration Equipment Co.,Ltd
Web site: www.chinatechco.com
Add: No.98. Yingchun East Road.Hailing Industrial Zoo.Taizhou City.Jiangsu Province.
ChinaTechco Cold/Freezer Room Technical Handbook
With Monoblock Unit

Table of Contents
Part I ChinaTechco Monoblock Unit ……………….…………3
Part II Installation…………………………………….………4-6
Part III Servicing manual…………………………...………7-10
Part IV Technical Drawings………………………………11-14

Part I
monoblock unit introduction
The monoblock units are composed of a condenser unit, an evaporator and a control panel, together in a single compact pack. This configuration allows the highest simplicity on the hand of installation, turning monoblock the most versatile, handy solution for all kind of cold / freezer room projects. The monoblock refrigeration unit can meet the freezing demand in the hotel, restaurant, hospital, agriculture, biology and chemical industry, the temperature of which can be kept with in0 - 8℃, -15- -25℃:
Monoblock units are equipped with:
Famous compressor brand: Maneurop, Danfoss, Copeland or Tecumseh. Reliable performance and long life-span with well known brand refrigeration parts. EBM fan motor, Castel Solenoid valve.
Danfoss high/ low pressure controller, Danfoss filter direr, Eliwell thermostat.
Self-supporting housing of galvanized plate Easily detachable front panels
Hermetic compressors with engine thermal insulation
Electronic control panel with 52 programmable parameters
Condensation by air.

Part II
NOTE: Installation and maintenance are to be performed only by qualified personnel who are familiar with local codes and regulations, and experienced with this type of equipment. CAUTION: Sharp edges and coil surfaces are a potential injury hazard. Avoid contact with them.
Installation schematic drawing
1.Monoblock Cooling/freezing Units, Panels, Doors, Service tools, Ice
pack and Shelves are packed separately in wooden cartons.
wooden cartons corner panel
2.Installation normally starts with the back wall panels or corner panel.
3.Wall panels and floor lock together with cam locks. cold/freezer rooms are erected from inside, so installation in confined areas is simple.
Monoblock Units roof
4.Monoblock Cooling/freezing Units are lifted into position and locked to wall panels by pop rivets or self-tapping screws.
Note: Remove power cable from casing to ensure it is on the outside
before setting roof.
5.Roof Panels installed last.
6.Affix Door handle and emergency release,
793 silicon joints between panels. Clean panels with cleaner and cloth provided.
monoblock unit wire.
Plug into duty
sharing power source
and allow to pull
down to temperature
in line with normal
good refrigeration
monoblock unit connecting wire 
8.Put up the shelves to either two or three walls.
9.Place the Ice pack on the shelves with holes.
Part III
Servicing Manual
Troubles   Possible Cause   Corrective Action  
  1. Power failure 1. Contact power company  
  2. Disconnect switch open 2. Close switch and check circuits  
  3. Burned-out compressor motor 3. Replace  
Compressor fails 4. Control circuit open 4. Locate cause and repair  
a. Overload protector tripped a. Check overload  
to start(no hum)  
b. Thermostat setting too high b. Set to lower temperature  
  c. Low-pressure control open c. Reset and check pressures  
  d. High-pressure control open d. Reset and check pressures  
  e. Loose wiring 5. Repair wiring  
  1. Improperly wired 1.Rewire unit  
  2.Determine reason and correct  
Compressor will 2. Low voltage to unit  
3.Replace compressor motor  
not start (hums 3. Burned-out compressor motor  
4. Replace compressor  
and trips 4. Mechanical problems in  
5.Install crankcase heater  
overload compressor  
protector) 5. Liquid refrigerant in compressor      
      1. Replace overload protector  
      2. Determine reason and correct  
      3. Determine reason and replace  
  1. Defective overload protector 4. Open compressor discharge  
  service valve. Purge possible  
  2. Low voltage to unit  
  overcharge of refrigerant. Provide sufficient  
  3. Defective run capacitor  
  condenser cooling air to unit  
  4. High discharge pressure  
  6. Properly charge system with  
  5. Suction pressure too low  
  refrigerant. Increase load on evaporator.  
  6. Suction pressure too high  
Compressor 7. Reduce air flow over evaporator.  
7. Compressor too hot  
starts and runs, Purge overcharge of refrigerant.  
8. Shorted motor winding  
but short cycles Replace compressor valves  
9. Dirty or iced evaporator  
  8. Properly charge system with  
  10. Low-pressure control differential  
  set too close  
  9. Replace compressor  
  11. High pressure control differential  
  10. Increase air flow over evaporator.  
  set too close  
  Replace broken belt. Replace  
  12. Erratic thermostat  
  defective fan motor.  
      11. Readjust differential.  
      12. Readjust or replace control  
      13. Relocate or replace thermostat  
  1. Short of refrigerant 1. Repair leak and recharge unit  

Unit operates 2. Thermostat contacts stuck 2. Clean contacts or replace thermostat.  
excessively closed 3. Check heaters, load and replace unit  
  3. Excessive load accordingly; replace  
  4. Evaporator coil iced insulation  
  5. Restriction in refrigerant system 4. Defrost unit and check operation  
  6. Dirty condenser 5. Locate and remove  
  7. Restricted air over evaporator 6. Clean condenser  
  8. Inefficient compressor 7. Determine cause and correct  
      8. Check compressor valves and  
      1. Reroute lines to provide proper pitch  
  1. Traps in hot gas and/or suction 2. Resize risers or install oil return traps  
  lines 3. Repair leak and recharge  
  2. Refrigerant velocity too low in 4. Adjust expansion valve; alter  
  risers refrigerant charge on capillary  
  3. Shortage of refrigerant tube system  
Compressor 4. Liquid refrigerant flooding back to 5. Add 1 pt of oil for each 10 1b of refrigerant  
compressor added to the factory charge  
loses oil  
5. Gas-oil ratio low 6. Clean or replace  
  6. Plugged expansion valve or 7. See items under entry “Compressor starts  
  strainer and runs, but  
  7. Compressor short cycling short cycles”  
  8. Superheat too high at 8. Change location of TXV bulb or adjust  
  compressor suction superheat to return wet  
      refrigerant to the compressor  
  1. Lack of compressor oil 1. Add oil to correct level  
  2. Reroute tubing  
  2. Tubing rattle  
  3. Repair mounting  
  3. Mounting loose  
  4. Adjust oil level or refrigerant  
  4. Oil slugging  
Compressor 5. Refrigerant flooding compressor  
5. Check expansion valve for leak or oversized  
noisy 6. Dry or scored shaft seal  
  7. Internal parts of compressor  
  6. Check oil level  
  broken or worn  
  7. Overhaul compressor  
  8. Compressor drive coupling  
  8. Tighten coupling and check  
  1. Ice or dirt on evaporator 1. Clean coil or defrost  
  2. Expansion valve stuck or dirty  
  2. Clean or replace expansion valve  
  3. Improper TXV superheat  
  3. Adjust expansion valve  
Unit low on adjustment  
4. Replace valve  
capacity 4. Wrong size expansion valve  
5. Adjust expansion valve  
  5. Excessive pressure drop in  
  6. Clean or replace strainer.  
  7.Subcool liquid or add refrigerant  
  6. Clogged strainer  

  7. Liquid flashing in liquid line      
  1. Control setting too high 1. Adjust control  
  2. Expansion valve too small  
  2. Replace valve  
  3. Evaporator too small  
  3. Replace coil  
  4. Insufficient air circulation  
Space 4. Correct circulation  
5. Shortage of refrigerant  
temperature To 5. Repair leak and recharge  
6. Expansion valve plugged  
high 6. Clean or replace  
7. Inefficient compressor  
  7. Check efficiency  
  8. Restricted or undersized  
  8. Clear restriction or resize lines  
  refrigerant Lines  
  9. Clean and defrost evaporator  
  9. Evaporator iced or dirty  
Suction line 1. Superheat setting too low 1. Adjust superheat setting  
2. Expansion valve stuck open 2. Clean or replace valve  
frosted or  
3. Evaporator fan not running 3. Correct problem  
4. Overcharge of refrigerant 4. Correct charge  
Liquid line 1. Restricted drier or strainer 1. Replace drier or strainer  
frosted or 2. Liquid line shut-off valve  
2. Open valve  
sweating Partially closed  
Hot liquid line 1. Expansion valve open too wide 1. Adjust expansion valve  
2. Refrigerant shortage 2. Repair leak and recharge  
Top of condenser 1. Refrigerant shortage 1. Repair leak and recharge  
Coils cool when 2. Refrigerant overcharge 2. Remove part of charge  
unit is operating 3. Inefficient compressor 3. Check efficiency and correct  
Unit in 1. Ice plugging expansion valve 1. Apply hot wet cloth to expansion valve  
body; an increase in suction pressure indicates  
vacuum-frost on orifice  
moisture; install  
expansion valve 2. Expansion valve strainer  
a new drier  
only plugged  
2. Clean strainer or replace valve  
  1. Overcharge of refrigerant 1. Purge overcharge  
  2. Air in system  
  2. Purge air  
High head 3. Dirty condenser  
3. Clean condenser  
pressure 4. Unit in too hot location  
4. Relocate unit  
  5. Water-cooled condenser  
  5. Clean or replace condense  
  1. Shortage of refrigerant 1. Repair leak and recharge  
  2. Cold unit location  
Low head 2. Provide warm condenser air  
3. Inefficient compressor valves  
pressure 3. Replace leaky valves  
4. Leaky oil return valve in oil  
  4. Repair or replace  
  1. Evaporator overloaded 1. See previous entry ″Unit operates  
High suction 2. Expansion valve stuck open excessively”  
3. Expansion valve too large 2. Repair or replace valve  
4. Leaking compressor suction valves 3. Replace valve  
  5. Evaporator too large 4. Replace suction valves or compressor  

      5. Resize evaporator  
  1. Shortage of refrigerant      
  2. Evaporator underloaded 1.Repair leak and recharge  
  3. Liquid line strainer clogged 2.Clean or defrost evaporator  
  4. Plugged expansion valve 3. Clean or replace strainer  
Low suction 5. Last charge on TXV power 4. Clean or replace valve  
assembly 5. Replace power assembly  
6. Space temperature too low 6. Adjust or replace thermostat  
  7. Expansion valve too small 7. Replace valve  
  8. Excessive pressure drop 8. Check for plugged external equalizer  
  through Evaporator 9. Resize compressor  
  9. Oversized compressor      
  1. Automatic defrost control      
  erratic or inoperative      
  2. Automatic defrost control 1. Replace control  
  improperly wired  
  2. Rewire control  
Evaporator coil 3. Defective defrost control thermal  
3. Replace control  
iced over element  
4. Relocate element  
  4. Improperly installed control  
  5. Replace or adjust control  
  thermal element  
  5. Defrost control termination point      
  too low      
  1. Defrost control incorrectly      
  2. Automatic defrost control 1. Rewire defrost control  
Cold room inoperative 2. Replace defrost control  
remains in 3. Defrost control termination point 3. Replace or adjust control  
defrost cycle too high 4. Clean or replace solenoid valve  
  4. Defrost solenoid valve stuck open 5. Relocate unit or provide heat  
  5. Room temperature too low(below      
  55°F or 12.8°C)      
  1. Drain tube plugged 1. Clean tube  
  2. Drain tube frozen  
  2. Check drain heater element and repair or  
  3. Split drain trough  
Water collects in replace  
4. Evaporator baffle not properly  
bottom of EMC 3. Replace trough  
cooler 4. Install baffle properly  
5. Humidiplate not adjusted properly  
  5. Adjust humidiplate  
  6. Door gasket not sealing  
  6. Adjust door or replace gasket  

Part IV
Technical Drawings
power wire
the lamp
monoblock unit
the door
installation schematic drawing
The monoblock unit structure:

monoblock unit structure
Cooling principle chart:
Cooling principle chart
    Electrical circuit diagram  
L — Voltage connection K2 — Lighting RJ — Themo relay
N  — Neutral connection K1 —Control connection  
M1 —Compressor JC — Contactor DC —ELECTROMAGNETISM
M2 — Condenser motor QJZ  — Crankcase heater  
M3 — Evaporator motor ZJC — Relay XR40C—E— Tempreture thermostat
Electrical principle chart
K--Start switch
W--Temp.control.power supply
HP--High ang low pressure switch
RJ--Overload relay
ZJ--Intermediate relay
ZJ1--Evap.fans intermediate relay
ZJ2--Condensing fans
intermediate relay
DC1--Defrosting solenoid valve
DC2--Refrigerating solenoid
M2--Condensing fans
M3--Evaporating fans
D1--Run light
D2--Defrosting light
D3--Overload light