DC Inverter U-match Series Cassette Type Unit 
60 
5.4.1.2 Work Procedure 
Work shall be undertaken under a controlled procedure so as to minimize 
the  risk  of  a  flammable  gas  or  vapour  being  present  while  the  work  is  being 
performed. 
5.4.1.3 General Work Area 
All maintenance staff and others working in the local area shall be instructed 
on  the  nature  of  work  being  carried  out.  Work  in  confined  spaces  shall  be 
avoided. The area around the workspace shall be sectioned off. Ensure that the 
conditions within the area have been made safe by control of flammable material. 
5.4.1.4 Checking for Presence of Refrigerant 
The area shall be checked with an appropriate refrigerant detector prior to 
and  during  work,  to  ensure  the  technician  is  aware  of  potentially  flammable 
atmospheres. Ensure that the leak detection equipment being used is suitable for 
use  with  flammable  refrigerants,  i.e.  non-sparking,  adequately  sealed  or 
intrinsically safe. 
5.4.1.5 Presence of Fire Extinguisher 
If  any  hot  work  is  to  be  conducted  on  the  refrigeration  equipment  or  any 
associated parts, appropriate fire extinguishing equipment shall be available to 
hand. Have a dry powder or CO2 fire extinguisher adjacent to the charging area. 
5.4.1.6 No Ignition Sources 
No  person  carrying  out  work  in  relation  to  a  refrigeration  system  which 
involves  exposing  any  pipe  work  that  contains  or  has  contained  flammable 
refrigerant shall use any sources of ignition in such a manner that it may lead to 
the  risk  of  fire  or  explosion.  All  possible  ignition  sources,  including  cigarette 
smoking,  should  be  kept  sufficiently  far  away  from  the  site  of  installation, 
repairing,  removing  and  disposal,  during  which  flammable  refrigerant  can 
possibly be released to the surrounding space. Prior to  work taking place, the 
area  around  the  equipment  is  to  be  surveyed  to  make sure  that  there  are  no 
flammable hazards or ignition risks. “No Smoking” signs shall be displayed.