GUIDE FOR THE USE OF HCs REFRIGERANTS R600a AND R290
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SYSTEM DESIGN SAFETY & PRACTICAL COMPRESSOR REPLACEMENT R600a and R290 are hydrocarbon refrigerants. They have consistent differences versus the HFCs or CHFCs that must be considered for designing, producing, testing, handling, storing, installing, repairing and disposing the applications, as well as for the workplaces and storage, with particular care to the flammability aspects and their consequences. A complete risk assessment of the use of HCs refrigerants must be carried out considering all the above points. It is also important to carefully consult the in use equipment manual. Only...

INTERNATIONAL SAFETY STANDARDS ! NOTE: Limit of 150g is for each separate refrigeration circuit. No restrictions in room size and occupancy category. SAFETY STANDARDS FOR ELECTRICAL APPLIANCES Electrical apparatus for explosive gas atmospheres Part 15: construction, testing and marking electrical components for use in explosive atmospheres For more information on these equipment and parts requirements, look at these two standards online. Always refer to local legislation as well.

HCs R600A AND R290 GENERAL INFORMATION AND CHARACTERISTICS SYSTEM DESIGN (1) Highly flammable substances are defined by a flammability limit of less than or equal to 0.10 kg/m3 at 21°C and 101 kPa or a heat of combustion greater than or equal to 19 kJ/kg; (according to ANSI/ASHRAE 34). (2) Practical limit according to EN 378-: it is used if the HC refrigerant of the system can leak into an occupied ambient. NOTE: HC refrigerants are classified in A3 Safety Class - lower toxicity, higher flammability, (according to ANSI/ASHRAE 34).

SYSTEM DESIGN R600A AND R290 IDENTIFICATION AND WARNING SYMBOLS The Embraco compressors for R600a and R290 have on the nameplate label - or as separate label - a warning symbol for flammable substances, even if they do not contain any refrigerants when delivered from Embraco factories. The refrigerant to be used is printed on the compressor label, also the compressor model includes a code identifying the refrigerant to be used. The R600a and R290 Embraco compressors are certificated by recognized testing agencies and adopt overload protectors and starting devices complying with the EN...

Same as R404A / R134a or slightly longer (10-15%) EXPANSION VALVES Specifically to R290. Heat Exchangers with smaller channels can help to minimize refrigerant charge under 150 grams Has to be spark free (shaded pole or ECM) Must be made in plastic or aluminium material OTHER ELECTRICAL COMPONENTS Have to be approved according to IEC 60079-15 (2005) Refrigerant Charge SYSTEM DESIGN FILTER DRYER NOTE: Values are just indicative; the proper refrigerant charge depends on the system design.

Common sense and staying alert will go a long way towards working safely with flammable refrigerants. Always conduct a risk assessment to determine whether it is appropriate to use a flammable gas refrigerant in the particular workplace. Hydrocarbon refrigerants do not have an odorant, so leaks can’t be identified by smell. A quality combustible gas leak detector is mandatory for HC service work. The work area must be free from sources of ignition such as naked flames and sparking electrical devices. Assure the presence of fire extinguisher equipment. This safe zone also applies around a...

SPECIFICATION OF TOOLS AND EQUIPMENT Use only tools and equipment certified for use in hazardous areas. (i.e. vacuum pump, electrical components and parts, original replacement parts). Normal vacuum pumps can be used if outside the flammable zone but the on/off switch must not be used, as this is usually the only ignition source in most pumps. It is anyway recommended to have a HC specific pump. Use leak detectors rated for combustible gas, if the leak cannot be located with a electronic detector, remove the charge, purge and fill with nitrogen and use a micro leak detector spray. For...

Use recovery machines specifically designed for HCs (they can also be used with HFCs). STANDARD RECOVERY MACHINES FOR HFCS MUST NOT BE USED WITH HC REFRIGERANTS BECAUSE OF SOURCES OF IGNITION SUCH AS SWITCHES, HIGH AND LOW PRESSURE CONTROLS AND RELAYS. Recovery cylinders: be specific for HC (pressure rating and the compatibility of valve seals, etc). Always check local requirements for handling, storage and transportation. REPLACEMENT OF ELECTRICAL PARTS In case of replacement of electrical parts inside the cabinet (i.e. neon lamp, thermostat, etc.): Sweep the worksite with the HC gas...

Replace failed components using original equipment parts NOTE: HCs are heavier than air, so if there is an internal leakage, there could be a high concentration of refrigerant in the bottom of the cabinet, creating a flammable mix. LEAKAGE Internal of cabinet HC leaks from evaporator to the internal compartment can form a flammable mixture. Any source of ignition (thermostat, on/off switches, etc.) may produce a flame or explosion. All electrical devices must be encapsulated or fire and explosion proof. External of cabinet The possibility of HC leakage external of the cabinet forming a...

Refrigerant Removal Disconnect cabinet from electrical supply. Remove the protective cover to access the compressor. Remove all the compressor electrical components. Fit a needle valve on the service tube. Connect a schrader valve in order to start the venting procedure. Remove the refrigerant by venting it in the atmosphere in an outside ambient away from heat and ignition sources. WARNING: During the refrigerant recovery (and generally when filling a vessel) take care to the amount (weight) of Refrigerant put in the vessel and to the weight of the vessel itself. Due to the different...

System evacuation Remove the needle valve and insert a schrader valve (to get a larger port). Make a 1st vacuum for at least 5 minutes. Fill the system with Nitrogen (OFDN) at 6 bar pressure (1st washing). Release the nitrogen and make a 2nd vacuum for 5 min. Fill the system with nitrogen at 6 bar (2nd washing). Release the nitrogen and make vacuum for 5 minutes. Fill the system with nitrogen at 6 bar (3rd washing). Release the nitrogen. Unsolder the line tubes at the compressor suction/discharge: this operation must be done immediately after. Remove old compressor and place the new one....