The 7.5 kg Split and the Category II Certificate
You hold a Category II F-Gas certificate and are sent to a small office block where a wall-mounted split system (R-410A, nameplate charge 7.5 kg, not hermetically sealed) has been losing capacity since spring. The building manager says the last documented leak check was 16 months ago and that the unit 'just needs a top-up'. While examining the outdoor unit you find oil staining at a flare joint on the liquid line. No leak detection system is fitted, and there is no service log on site. Your supervisor asks you to confirm the charge, add refrigerant to bring the unit back to duty and invoice the call-out before you leave.
1. May you legally carry out this repair and recharge yourself? What should you actually do?
Read the worked answer
No. Category II certification is limited to equipment containing less than 3 kg of F-gas, and to hermetically sealed equipment containing less than 6 kg. This is a non-hermetically-sealed split with a 7.5 kg nameplate charge, so it exceeds both limits and the work sits in Category I.
What to do instead:
- Do not open, repair or charge the circuit. Make it safe and leave it isolatrated.
- Confirm the charge from the nameplate and record what you found (oil staining, suspected flare leak).
- Tell the building manager in writing that the work must go to a Category I certified technician, and why.
- Do not let the visit be closed out as a routine 'top-up'. Topping up a known leak without repairing it is exactly what the containment rules exist to prevent, and it would hide the operator's overdue leak-check failure.
2. What is the correct periodic leak-check interval for this system, and what does the leak you found trigger?
Read the worked answer
Charge in CO2 equivalent = 7.5 kg × 2088 (GWP of R-410A) = 15,660 kg CO2e = 15.66 t CO2e.
That falls in the 5 t to under 50 t band, so the periodic leak check is every 12 months (it would only be 24 months if a leak detection system were fitted - it is not).
Consequences:
- The last check 16 months ago means the system is overdue; that is the operator's infringement, and you should flag it rather than paper over it.
- The leak you found must be repaired without undue delay, and a confirmation leak check must be carried out within one month of the repair. That confirmation check is additional to the periodic schedule, not a replacement for it.
- If the leak cannot be repaired, the operator must not simply keep running it unmanaged; the situation has to be documented and a repair plan put in place.
3. What records and labelling must exist for this unit, and who is responsible?
Read the worked answer
The operator is responsible for the records; the certified technician/company must supply the data and keep their own copy.
Records required for equipment at or above 5 t CO2e:
- Type and quantity of gas installed (from the nameplate / commissioning data)
- Quantity added at each service and quantity recovered
- Date and result of every leak check, including the post-repair confirmation check
- Name of the certified company and the certificate number of the technician
- Retained for at least 5 years
Label requirements:
- Refrigerant designation and, for a blend, its composition
- Charge in kg and in t CO2e
- GWP of the gas
- Updated whenever the charge or the refrigerant changes
In this case the missing service log is itself a finding you should record on your own paperwork when you hand the job over.