Sealey SAC16000 Instructions Manual page 7

exists that could compromise safety, then no electrical supply shall be connected to the circuit until it is satisfactorily dealt with. If the
fault cannot be corrected immediately but it is necessary to continue operation, an adequate temporary solution shall be used. This
shall be reported to the owner of the equipment so all parties are advised. Initial safety checks shall include:
• That capacitors are discharged: this shall be done in a safe manner to avoid possibility of sparking.
• That no live electrical components and wiring are exposed while charging, recovering or purging the system.
• That there is continuity of earth bonding.
6.4.10. REPAIRS TO SEALED COMPONENTS
During repairs to sealed components, all electrical supplies shall be disconnected from the equipment being worked upon prior to
any removal of sealed covers, etc. If it is absolutely necessary to have an electrical supply to equipment during servicing, then a
permanently operating form of leak detection shall be located at the most critical point to warn of a potentially hazardous situation.
Particular attention shall be paid to the following to ensure that by working on electrical components, the casing is not altered in such a
way that the level of protection is affected. This shall include damage to cables, excessive number of connections, terminals not made
to original specification, damage to seals, incorrect fitting of glands, etc. Ensure that the apparatus is mounted securely. Ensure that
seals or sealing materials have not degraded to the point that they no longer serve the purpose of preventing the ingress of flammable
atmospheres. Replacement parts shall be in accordance with the manufacturer's specifications.
6.4.11. REPAIR TO INTRINSICALLY SAFE COMPONENTS
DO NOT apply any permanent inductive or capacitance loads to the circuit without ensuring that this will not exceed the permissible
voltage and current permitted for the equipment in use. Intrinsically safe components are the only types that can be worked on while
live in the presence of a flammable atmosphere. The test apparatus shall be at the correct rating. Replace components only with parts
specified by the manufacturer. Other parts may result in the ignition of refrigerant in the atmosphere from a leak.
6.4.12. CABLING
Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges or any other adverse
environmental effects. The check shall also take into account the effects of aging or continual vibration from sources such as
compressors or fans.
6.4.13. DETECTION OF FLAMMABLE REFRIGERANTS
Under no circumstances shall potential sources of ignition be used in the searching for or detection of refrigerant leaks. A halide torch
(or any other detector using a naked flame) shall not be used.
Removal and evacuation When breaking into the refrigerant circuit to make repairs – or for any other purpose – conventional
procedures shall be used. However, for flammable refrigerants it is important that best practice is followed since flammability is a
consideration. The following procedure shall be adhered to:
• Remove refrigerant;
• Purge the circuit with inert gas;
• Evacuate;
• Purge with inert gas;
• Open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery cylinders. For appliances containing flammable refrigerants the
system shall be purged with oxygen-free nitrogen to render the appliance safe for flammable refrigerants. This process may need to
be repeated several times. Compressed air or oxygen shall not be used for purging refrigerant systems. For appliances containing
flammable refrigerant, purging shall be achieved by breaking the vacuum in the system with oxygen-free nitrogen and continuing to
fill until the working pressure is achieved, then venting to atmosphere, and finally pulling down to a vacuum. This process shall be
repeated until no refrigerant is within the system. When the final oxygen-free nitrogen charge is used, the system shall be vented down
to atmospheric pressure to enable work to take place. This operation is absolutely vital if brazing operations on the pipe-work are to
take place.
Ensure that the outlet for the vacuum pump is not close to any potential ignition sources and that ventilation is available.
6.4.14. CHARGING PROCEDURES
In addition to conventional charging procedures, the following requirements shall be followed.
• Ensure that contamination of different refrigerants does not occur when using charging equipment. Hoses or lines shall be as short as
possible to minimise the amount of refrigerant contained in them.
• Cylinders shall be kept in an appropriate position according to the instructions.
• Ensure that the refrigerating system is earthed prior to charging the system with refrigerant.
• Label the system when charging is complete (if not already).
• Extreme care shall be taken not to overfill the refrigerating system.
Prior to recharging the system, it shall be pressure-tested with the appropriate purging gas. The system shall be leak-tested on
completion of charging but prior to commissioning. A follow up leak test shall be carried out prior to leaving the site.
6.4.15. DECOMMISSIONING
Before carrying out this procedure, it is essential that the technician is completely familiar with the equipment and all its detail. It is
recommended good practice that all refrigerants are recovered safely. Prior to the task being carried out, an oil and refrigerant sample
shall be taken in case analysis is required prior to re-use of recovered refrigerant.
It is essential that electrical power is available before the task is commenced.
A) Become familiar with the equipment and its operation.
B) Isolate system electrically.
C) Before attempting the procedure, ensure that:
• Mechanical handling equipment is available, if required, for handling refrigerant cylinders.
• All personal protective equipment is available and being used correctly.
• The recovery process is supervised at all times by a competent person.
• Recovery equipment and cylinders conform to the appropriate standards.
D) Pump down refrigerant system, if possible.
E) If a vacuum is not possible, make a manifold so that refrigerant can be removed from various parts of the system.
F) Make sure that cylinder is situated on the scales before recovery takes place.
G) Start the recovery machine and operate in accordance with instructions.
H) Do not overfill cylinders (no more than 80 % volume liquid charge).
I) Do not exceed the maximum working pressure of the cylinder, even temporarily.
J) When the cylinders have been filled correctly and the process completed, make sure that the cylinders and the equipment are
© Jack Sealey Limited Original Language Version
SAC16000 Issue 1 03/01/24