LG Multi F MAX Distribution Box
The genuine LG branch distribution unit that splits refrigerant from a Multi F MAX outdoor unit to two, three or four indoor units.
AirGreen codeAG-AC-01503
514 316-2973 · sales@airgreen.ca
Quick facts
The LG Multi F MAX distribution box (BD) sits between the outdoor unit and the indoor units of an LG Multi F MAX multi-zone system. It takes the main refrigerant line and splits it to two, three or four heads. LG states that at least one box is required to operate the outdoor unit.
More flexibility in placing the indoor units
With one or two boxes close to the rooms being served, the long lines run from the box rather than from the outdoor unit. The ZR versions are designed for Multi F MAX and Multi F MAX with LGRED° units running on R-32, including the KUMXB481A. The internal components are insulated and the box is installed inside the building.
Four models
- PMBD3620ZR: 2 ports, 48,000 BTU/h total.
- PMBD3630ZR: 3 ports, 72,000 BTU/h total.
- PMBD3640ZR: 4 ports, 73,000 BTU/h total.
- PMBD3641ZR: 4 ports, with port D in 1/2 in for a 36,000 BTU/h unit, with adapters supplied by LG.
Connections and piping limits
On the outdoor unit side, the box is brazed at 3/8 in (liquid) and 3/4 in (gas). On the indoor unit side, the ports are 1/4 in and 3/8 in flare connections. LG limits piping to 49.2 ft between the box and an indoor unit, with a maximum elevation difference of 32.8 ft. Power supply is 208-230 V; field wiring includes 3 conductors of 14 gauge and 2 of 18 gauge.
Installed by AirGreen in Greater Montréal
We design the piping layout for your Multi F MAX, install the boxes and handle commissioning in Montréal, Laval, Longueuil, on the South Shore and on the North Shore. RBQ licence 5645-9605-01. For availability or a quote, call us at 514 316-2973 or email sales@airgreen.ca with the outdoor unit model and the number of heads.
The distribution point of a Multi F MAX system
Multi F MAX indoor units do not connect straight to the outdoor unit: they go through one or more branch distribution units.
- Refrigerant distribution to 2, 3 or 4 indoor units
- LG Multi F MAX outdoor units, including the KUMXB481A
- Large homes and small businesses where heads are far from the outdoor unit
- A 36,000 Btu/h port on the PMBD3641ZR for a larger indoor unit
4 sizes, one page
Each size has its own AirGreen code. Tap a row to select it.
| Model | Part no. | Ports to indoor units | Indoor-unit connections | Maximum unit capacity | Rated current | Net weight | AirGreen code |
|---|---|---|---|---|---|---|---|
| PMBD3620ZR | PMBD3620ZR | 2 (A, B) | Liquid 1/4 in, vapor 3/8 in, flare | 48,000 Btu/h | 0.34 A | 17.4 lb | AG-AC-01501 |
| PMBD3630ZR | PMBD3630ZR | 3 (A to C) | Liquid 1/4 in, vapor 3/8 in, flare | 72,000 Btu/h | 0.36 A | 18.3 lb | AG-AC-01502 |
| PMBD3640ZR | PMBD3640ZR | 4 (A to D) | Liquid 1/4 in, vapor 3/8 in, flare | 73,000 Btu/h | 0.4 A | 19.4 lb | AG-AC-01503 |
| PMBD3641ZR | PMBD3641ZR | 4 (A to D), port D up to 36,000 Btu/h | Liquid 1/4 in; vapor 3/8 in (A to C) and 1/2 in (D), flare | 73,000 Btu/h | 0.4 A | 19.6 lb | AG-AC-01504 |
Number of ports to indoor units. The PMBD3641ZR takes a 36,000 Btu/h unit on port D.
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- The unit goes inside the building, with LG’s service clearance around the access panel.
- Between the BD unit and an indoor unit: 49.2 ft of piping and 32.8 ft of height difference at most.
- Between two BD units: 49.2 ft of height difference at most.
- Field wiring: 3 × 14 AWG for power and 2 × 18 AWG for communication.
- Ports A to C take indoor units from 7,000 to 24,000 Btu/h.
Manufacturer documents
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Frequently asked questions
How many BD units does my system need?
At least one. LG offers 2-, 3- and 4-port units; the count depends on the number of indoor units and where they are. Send us the outdoor unit model and the list of heads and we run the numbers.
What is the difference between PMBD3640ZR and PMBD3641ZR?
Both have four ports. On the PMBD3641ZR, port D has a 1/2 in vapor connection and takes a 36,000 Btu/h indoor unit; LG supplies the adapters for that connection.
Does it work with the older R-410A PMBD3620?
The ZR models are the versions for R-32 Multi F MAX outdoor units. Give us your outdoor unit model number and we confirm the matching BD unit.
Can you install it?
Yes. We lay out the piping, install the BD units and commission the system, everywhere in Greater Montréal.
Genuine branch distribution units for your Multi F MAX
Tell us the size and the quantity: we confirm availability and send you a quote. Or let our technicians install it for you.
Specifications from the manufacturer’s documentation, checked on October 7, 2026.