AcmeLink series · Compact indoor-unit gateway
AcmelLink_B27 Compact VRF Gateway
A compact gateway for one air-conditioning indoor unit. The 51 × 53 × 17 mm housing fits suitable wall back boxes and service spaces, with Bluetooth brand-adaptation upgrades through a WeChat mini program.
| Model | AcmelLink_B27 |
|---|---|
| Gateway allocation | One gateway per indoor unit |
| Dimensions | 51 x 53 x 17 mm |
| Power source | Compatible air-conditioning indoor unit |
| Average power consumption | 0.5 W |
One indoor unit. One gateway.
Install one AcmelLink_B27 for each indoor unit. Multiple gateways can be networked through the selected wired or wireless interface for coordinated control. This is a different architecture from AcmeLink GW centralized control, where one gateway can serve multiple indoor units on a supported system bus.
Indoor unit 2 ↔ B27 gateway 2
Each gateway → Selected smart-home or host interface
Concealed installation in a small space
The compact enclosure can be installed in a suitable 86-type electrical back box or at the indoor-unit service opening. Check available space, access and cable routing. Power comes from the compatible indoor unit; average consumption is 0.5 W.
The auxiliary DC 7–15 V, 0.7 W maximum connection is an output for a compatible panel. It is not a mains supply input. Isolate power before wiring and keep signal connections separated from AC mains.
Adapt the brand through a WeChat mini program
Use the Bluetooth-connected WeChat mini program to upgrade the gateway for a supported HVAC brand. This helps installers match the gateway to a project on site. Confirm the full indoor-unit model, matching firmware and physical connection before changing brands.
- Open the Gateway Bluetooth Configuration mini program and connect to the correct gateway.
- After Bluetooth connection, briefly press SET to obtain control permission.
- Use the matching brand firmware and delivery-specific upgrade instructions.
- Check unit discovery, supported controls and any original-controller coexistence settings after upgrading.
Contact ACMELEC for the current mini-program entry and matching upgrade package. Firmware adaptation does not make every model or terminal arrangement compatible.
Select the interface and retain the right controller
The manual describes RS485, Zigbee, BLE and WiFi integration options, with platform-specific configurations for Xiaomi, Huawei, Alibaba and Tuya. Specify the required interface and platform when ordering; these are configuration options rather than a promise that every protocol is enabled together.
A compatible third-party control panel can be connected where required. Keeping the original wired controller depends on the exact HVAC model; some routes need a primary/secondary setting and some do not permit coexistence.
Brand connection reference
The manual lists the following routes. Match the complete model, connector, polarity and original controller before ordering. The English manual includes the full terminal table and coexistence settings.
| HVAC system | Gateway terminals | HVAC terminals | Polarity matters | Cable cores | Original controller |
|---|---|---|---|---|---|
| Daikin VRV/VRF | P1, P2 | P1, P2 | No | 2 | Yes |
| Hitachi VRF | P1, P2 | A, B | No | 2 | Yes* |
| Hitachi US | A1, B1, X, Y | CN2 | Yes | 4 | No |
| Hisense VRF | P1, P2 | A, B | No | 2 | Yes |
| York VRF | P1, P2 | A, B | No | 2 | Yes |
| Toshiba VRF | X, Y | A, B | No | 2 | Yes |
| Panasonic VRF | X, Y | Outer 2 pins of CN041 | No | 2 | Yes |
| Mitsubishi Heavy Industries VRF | P1, P2 | X, Y | No | 2 | Yes |
| Mitsubishi Heavy Industries VRF (3-wire) | A1 and B1 joined; X, Y | CNB | Yes | 3 | No |
| Midea VRF | A1, X, Y | CN20 | Yes | 3 | Yes |
| Midea Cool Wind | A1, B1, X, Y | CN40 | Yes | 4 | No |
| Gree generation 5 VRF | P1, P2 | H1, H2 | No | 2 | Yes |
| Haier VRF | X, Y, B1 | A, B, C | Yes | 3 | No |
| Haier ducted | A1 and B1 joined; X, Y | C, B, A | Yes | 4 | No |
| Gree ducted (2-wire) | A1, B1 | COM_MANUAL pins 3, 2 | Yes | 2 | Yes |
| Gree ducted (4-wire) | A1, B1, X, Y | CN5 or CN6 | Yes | 4 | No |
| Daikin MX | A1, B1, X, Y | S21 | Yes | 4 | No |
| Mitsubishi Electric (Lingyao) | A1, B1, X, Y | CN105 | Yes | 4 | Yes |
| Hisense ducted (N+) | A1, B1, X, Y | WiFi terminal | Yes | 4 | Yes |
* Hitachi coexistence has controller-specific exceptions. Consult the manual and confirm the actual wiring with ACMELEC.
Indicators and service information
| LED | State | Meaning |
|---|---|---|
| RUN | Steady on | Indoor unit found; normal operation |
| RUN | Fast flashing | Searching for the indoor unit |
| RUN | Off | No indoor unit found |
| STA | Steady on | Air conditioner on |
| STA | Fast flashing | Air-conditioning fault |
| STA | Slow flashing | Third-party control-panel fault |
| STA | Off | Air conditioner off |
| RUN + STA | 3 fast flashes | Bluetooth connection established |
Bluetooth diagnostics can display available operating parameters and fault codes. Supported points vary by indoor unit and firmware. The documented gateway ID range is 1–32 for host addressing; each gateway still serves one indoor unit.
English manual and project enquiry
Download AcmelLink_B27 English manual
Send the HVAC brand and full indoor-unit model, terminal photos, quantity, original controller model, target platform and destination country. Configuration and pricing are confirmed through B2B project discussion.
AcmelLink_B27 buyer questions
How many indoor units can one AcmelLink_B27 control?
One gateway is paired with one indoor unit. For multiple indoor units, provide one gateway per unit and connect the gateways through the selected wired or wireless integration.
Can it fit inside a wall back box?
Its 51 x 53 x 17 mm housing is designed for concealed installation in a suitable 86-type back box or an indoor-unit service opening. Check available space, cable routing and separation from mains wiring.
Can the HVAC brand be changed on site?
Yes. The gateway supports brand-adaptation upgrades through a WeChat mini program using Bluetooth. Confirm the exact indoor-unit model, wiring and matching firmware before upgrading.
Can I keep the original wired controller?
Only where the exact HVAC system supports coexistence. Some controllers require primary/secondary configuration; other routes do not permit the original controller to remain connected. See the compatibility table.
Does every unit include WiFi, Zigbee and RS485?
The manual describes RS485, Zigbee, BLE and WiFi integration options. Confirm the ordered configuration and target platform; do not assume every interface or platform is enabled in one unit.
How does B27 differ from AcmeLink GW?
B27 is a compact one-gateway-per-indoor-unit solution. AcmeLink GW provides centralized control of multiple indoor units on a supported system communication bus.
A compact HVAC gateway for room-by-room integration
B27 is the single-indoor-unit option for projects where the gateway is installed near each indoor unit or in a suitable wall back box. Its 51 × 53 × 17 mm enclosure suits installations with limited space, subject to clearance, cable routing and access for service.
For a project with eight indoor units using the B27 architecture, plan eight gateways. Specify the interface and host platform separately: gateway quantity does not confirm the capacity or compatibility of the selected network.
Prepare B27 for your destination market
Provide the complete indoor-unit and existing controller models, terminal photos, destination country and target automation platform. Confirm the ordered wired or wireless interface, controller coexistence and availability of the WeChat mini-program commissioning route for the installing team.
Before volume ordering, test a sample on the intended indoor unit, including the matching brand firmware, supported commands, feedback and restart behavior. A brand upgrade still requires the correct physical interface and a supported model.
Compare B27 with a centralized VRF gateway. For multiple indoor units on one supported system bus, review AcmeLink GW B19 centralized control.
Model reference and gateway selection
AcmelLink_B27 is also referred to as B27, AcmeLink B27 Gateway, AcmeLink_B27_GATEWAY. These names refer to this product route; specify the ordered configuration when requesting a sample or quotation.
Compare B19, B27, B25L, ME and DK · Read the matching B27 manual
Also consider B25L
AcmeLink B25L follows the one-gateway-per-indoor-unit approach in an 85 × 85 × 28 mm enclosure. Compare its own connector table, auxiliary output and host configuration with B27 before selecting the installation.
Documentation and source references
One gateway per indoor unit, with a 51 × 53 × 17 mm enclosure. AcmelLink_B27 is the manual model name; AcmeLink B27 and B27 refer to this product on the website.
Source: AcmelLink_B27 English product manual. English edition dated 15 September 2026, based on the supplied V1.4 technical manual dated 18 May 2022.
- Hardware specifications and one-gateway-per-unit allocation — PDF page 2
- Brand connection tables (pages 4–5) — PDF page 4
- Original-controller coexistence and precautions — PDF page 6
- Bluetooth commissioning and brand adaptation — PDF page 7
Page numbers above refer to the PDF viewer. Documentation references checked on . This is a document cross-check, not a new installation test or a change to the supported-model list.
For your order, confirm the complete HVAC model, firmware, interface and required functions. How we handle technical sources and corrections.