Braemar MCMX VRF — Refrigerant Reclaim / Vacuum (Pump‑Down) Mode

⚠️ Safety Notice – Reverse Cycle Air Conditioners

This equipment must only be installed, commissioned, serviced and repaired by suitably qualified and licensed personnel.

Before commencing work, complete a task-specific risk assessment and ensure electrical isolation procedures, safe access, adequate service clearances and appropriate PPE have been considered. All work must comply with applicable regulations, standards and manufacturer requirements.

Particular care must be taken when working around electrical systems, refrigerant circuits, moving parts, roof spaces, ceiling spaces, confined spaces and working-at-heights hazards where applicable.

Do not proceed if safe access, required clearances, confined space risks or appropriate safety controls cannot be achieved and maintained. 

Safety takes priority over diagnosis, repairs, installation schedules and customer expectations. If the task cannot be completed safely, it must not proceed until the risks have been adequately controlled.

Applies to:
Braemar MCMX VRF multi‑split outdoor units
(MCMX080D104 / 100D105 / 120D107 / 140D108 / 160D109)

Purpose

This article explains the approved methods technicians can use to place the system into a condition where refrigerant can be safely recovered (reclaimed) from a Braemar MCMX VRF system.

It also clarifies the difference between:

• A2 – Refrigerant Recovery Operation
• A8 – Aftersales Vacuum Mode

to ensure the correct function is used.

⚠️ Safety & Compliance

• Only qualified, licensed refrigeration technicians may perform refrigerant recovery
• Australian Greenhouse Office regulations apply
• Do not vent refrigerant to atmosphere under any circumstances
• Use approved recovery unit and cylinders
• Isolate mains power before disconnecting hoses or opening the system
• Follow PPE and site safety requirements

✅ Function Overview — A2 vs A8 (Critical for Correct Use)

✅ Important Clarification

• A2 does NOT open all valves — it is a controlled system recovery process
• A8 DOES open all valves — this is required to reclaim the entire system

➡ If the compressor is faulty or system cannot run:
A8 must be used

Overview of Options

There are two approved methods to place the system into a condition for refrigerant recovery:

Option 1 — Operational Pump‑Down via Cooling Run

Use only when:

• System is operational
• Compressor runs normally

Steps:

1. Command all indoor units to Cooling at lowest set temperature
2. Allow system to reach steady operation
3. Turn OFF power at outdoor isolator
4. Reclaim refrigerant using recovery unit

Result:

• Valves remain open from operation
• Enables full system recovery

⚠️ Use only when system operates without fault

Option 2 — Outdoor PCB Function A8: Vacuum / Pump‑Down Mode

Use when:

• Compressor is faulty
• System cannot run
• Full recovery is required

✅ Function Behaviour (Important)

When A8 is activated:

• All EXVs open
• System valves open across pipework and IDUs
• System becomes fully accessible for recovery

➡ This allows complete refrigerant reclaim using external equipment

A) 4‑Button MCMX Outdoor PCB

1. Ensure system is in Standby (power ON, unit OFF)
2. Press and hold SW1 for ~5 seconds (enter Function Settings)
3. Use SW1 / SW2 to scroll to A8
4. Press SW3 (OK)
5. Select 01 — Vacuum / Pump‑Down Mode
6. Press SW3 to confirm

➡ All valves open for recovery

1. Turn power OFF at isolator
2. Perform reclaim

B) 7‑Button MCMX Outdoor PCB (older models)

1. Ensure system is in Standby
2. Press SW3 (Function)
3. Scroll to A8
4. Press SW7 (OK)

➡ All valves open

1. Turn power OFF
2. Perform reclaim

After Recovery

• Restore power
• System returns to Off / Standby

Notes & Supporting Manual References

• Function Settings (A‑codes): Pages 28–31
• Service Modes (including recovery & vacuum): Pages 24–27
• Removal & Disposal: Pages 36–37

✅ Technician Checklist (Quick Reference)

• ✔ Confirm licensed technician and equipment
• ✔ Identify correct method:
  • System operational → Option 1
  • System faulty → A8
• ✔ Confirm PCB type (4‑button / 7‑button)
• ✔ If using A8 → confirm function is activated and confirmed
• ✔ Turn power OFF before recovery
• ✔ Recover full charge into approved cylinder
• ✔ Repair / leak test
• ✔ Evacuate system (≥ 100 µPa per install guidance)
• ✔ Restore power and confirm standby

?️ Troubleshooting

Cannot enter function mode

• Ensure:
  • Unit powered ON
  • In Off / Standby
  • Debugging / preheat complete (if recent install or PCB replacement)

EXVs not opening / recovery slow

• Confirm:
  • A8 selected and confirmed (not just displayed)
• Check:
  • Communication faults
  • PCB or system errors

Recovery incomplete

• A2 used instead of A8
• A8 not confirmed correctly
• System not fully opened

? Related References

• Outdoor PCB Function Map (A‑codes): Pages 28–31
• Debugging & Addressing: Pages 20–23
• Refrigerant charging data: Pages 18–19

⚡ Quick Guide — Field Use

✅ If system works normally

Cooling mode → Stabilise → Power OFF → Reclaim

✅ If system is faulty (correct method)

Enter A8 → Confirm → Power OFF → Reclaim

✅ PCB Shortcuts

4‑Button

Hold SW1 → A8 → OK → 01 → OK → Power OFF → Reclaim

7‑Button

SW3 → A8 → SW7 → Power OFF → Reclaim

✅ Key Takeaway

A2 = system moves refrigerant (compressor required)
A8 = system fully opens for reclaim (no compressor required)