The GLMZK-TG120 is a hotel guest room control unit (RCU) manufactured by
Shenzhen GLMZK Intelligent Electric Co., Ltd., a guest room control system
manufacturer in Shenzhen, China. One unit provides 8 constant-voltage PWM dimming
channels at DC 24 V, 4 relay outputs rated 10 A / 250 V AC,
12 potential-free dry contact inputs, one RS485 master port,
a dedicated door display port and a built-in network gateway — no separate
gateway hardware is required. The guest room operates fully standalone, with no network or
cloud service needed for normal use.
GLMZK-TG120 hotel room control unit. Export version shown, with English terminal labelling.
Quick specification
Model
GLMZK-TG120
Product type
Hotel guest room control unit (RCU) — full-dimming, for 24 V LED lighting schemes
Dimming outputs
8 × constant-voltage PWM, DC 24 V, common anode, 5 A (120 W) per channel
Relay outputs
4 × 10 A / 250 V AC resistive, 1 Form A, AgSnO₂In₂O₃ contacts
Dry contact inputs
12 × potential-free (6 general + 6 dedicated: PIR ×3, SOS, doorbell, door contact)
Bus
RS485 master, proprietary protocol, 9600 bps 8-N-1, up to 800 m, up to 32 devices
Network
1 × RJ45 Ethernet, gateway function built in
Door display
1 × dedicated RJ45 port (not Ethernet), standard network cable, T568B
Supply voltage
DC 24 V from an external switch-mode power supply (24 V / 400 W recommended)
Power consumption
< 3 W standby, < 8 W maximum (excluding connected load)
Dimensions
238.5 × 109 × 45 mm (L × W × H)
Weight
1.5 kg net
Mounting
Screw mounting as standard; optional clips for 35 mm DIN rail (approx. 240 mm of rail)
Housing
Metal housing; every port labelled with the connected device and its number (English labelling on export versions)
Operating temperature
−10 to +55 °C, 5–95 % RH non-condensing
Certification
CE assessment (EMC 2014/30/EU, LVD 2014/35/EU) not yet completed — can be arranged for project supply. RoHS not yet tested; can be arranged.
Warranty
24 months
Lead time
30 working days after order confirmation
Minimum order quantity
No fixed MOQ. The GLMZK-TG120 is a customised product and is quoted per project; sample and mock-up room quantities are accepted.
Packing
248 × 119 × 55 mm per unit carton; 1.5 kg net
Country of origin
Made in China
Key features
Network gateway built in. Each RCU is its own gateway; no separate gateway hardware is required.
Operates fully standalone. No network or cloud service is needed for normal room operation. Ethernet is used for remote commissioning, diagnostics and management.
Flicker-free dimming. PWM frequency ≥ 5 kHz, dimmable down to 1 % brightness, with no visible banding on camera.
Three-level protection. A replaceable 10 A blade fuse on every dimming channel, a 20 A fuse shared by the four relay outputs, a 2 A fuse on the control circuit, plus on-board over-temperature protection with automatic reset.
60 V / 20 A MOSFET on every dimming channel (RDS(on) < 35 mΩ) — approximately four times the 5 A channel rating, giving substantial thermal and surge margin.
Certified relay components. AgSnO₂In₂O₃ contacts, UL (E164730), TÜV (R50223752) and CQC certified; electrical life 100,000 operations at 10 A resistive, mechanical life 1,000,000 operations.
Two independently powered dimming groups. Link them to share one 24 V / 400 W supply for a typical guest room, or give each group its own supply for up to 800 W total.
RS485 terminals carry 12 V. Panels, thermostats and IR repeaters take data and power from a single 4-core cable.
Door display wired with standard network cable (T568B) — no special training for the cabling contractor.
Real-time clock with battery backup and local configuration storage; time, scenes and settings survive a power failure.
Terminals sized for real site work. Barrier terminals accept 2 × 2.5 mm² per position; each dimming group has two positive positions so four luminaire positives land comfortably.
Mains and low-voltage terminals on opposite sides of the unit, keeping the two systems physically separated.
Technical specification
Dimming outputs
Channels and type
8 × constant-voltage PWM dimming outputs, DC 24 V, common anode, for 24 V LED luminaires
Grouping
2 groups of 4 channels, each with its own power input terminal
Per-channel capacity
Max 5 A (120 W) per channel
Per-group capacity
Limited by the supply assigned to that group; ≤ 400 W per group with a 24 V / 400 W supply
Power configuration
For typical guest-room loads the two groups can be linked to share a single 24 V / 400 W supply; for higher loads each group takes its own supply, giving up to 800 W total
Control power
Power input 1 also supplies the RCU control circuit and must always be connected
Minimum dimming level
1 %
PWM frequency
≥ 5 kHz — flicker-free
Power stage
60 V / 20 A N-channel MOSFET per channel, RDS(on) < 35 mΩ
Short-circuit protection
Individually replaceable 10 A blade fuse per channel; a short circuit on one channel does not affect the others
Luminaire requirement
24 V DC constant-voltage LED luminaires only. 230 V AC luminaires must be connected to the relay circuits.
Supply wiring
Install the power supply close to the unit; ≤ 3 m recommended, 2.5 mm² copper conductors
Relay outputs
Channels and rating
4 × relay outputs, 10 A / 250 V AC resistive; TV-5 250 V AC (5 A tungsten lamp load)
Contact form
1 Form A (SPST, normally open)
Contact material
AgSnO₂In₂O₃ — resistant to welding under inrush, suitable for lamp and inductive loads
Relay life
Electrical 100,000 operations at 10 A resistive; mechanical 1,000,000 operations
Relay certification
UL E164730, TÜV R50223752, CQC certified components
Circuit allocation
1 relay drives an AC contactor that switches all controlled socket circuits in the room; 3 relays directly control non-dimmed circuits such as the bathroom extractor fan
Design note
The relay carries only the contactor coil, not the socket load, which significantly extends contact life
230 V LED derating
≤ 2 A per channel when switching 230 V LED luminaires
Combined limit
The four relay outputs share a single 20 A fuse; their combined current must not exceed 20 A
AC contactor
Selected and purchased by the customer according to the actual load; not part of our scope of supply
Communication
RS485
1 × RS485 port; the RCU acts as bus master for GLMZK panels, thermostats and IR repeaters. The bus is brought out on two 4-position terminals (A / B / G / V) — the same bus twice, so it can be looped in and out. Each terminal carries a 12 V output.
Protocol
Proprietary protocol
Baud rate / format
9600 bps, 8-N-1
Max bus length
800 m
Max devices per bus
32
Ethernet
1 × RJ45 with magnetics, for connection to the hotel network
Gateway function
Built into the RCU — each unit is its own gateway
Standalone operation
Normal room operation does not require a network connection
Cloud management
Optional
Door display interface
Interface
1 × dedicated RJ45 port (not Ethernet), wired with standard Cat5e/Cat6 cable, plug crimped to T568B
Signals
Make-Up-Room (MUR), Do-Not-Disturb (DND), Please-Wait, occupancy status, plus 12 V supply for the door display
Max cable length
≤ 3 m between the RCU and the door display
Door panel max current
2 A
Important
The door-display port and the network port use identical RJ45 connectors but are not interchangeable. Both are labelled on the housing. Never connect the door-display port to a network switch.
Inputs
Dry contact inputs
12 × potential-free: 6 general signal inputs (IN 3–8) plus 6 dedicated inputs (PIR, PIR 2, PIR 3, SOS, doorbell, door contact). Each 8-position terminal provides 12 V and common, so connected devices can be powered from the unit.
Typical use of general inputs
Card holder, occupancy sensor, window contact, service call, smoke or water alarm, minibar or safe status
Mains detection
Mains-detection input (N and L) for monitoring supply status
Analogue inputs
None
Temperature measurement
Not measured by the RCU — room temperature is sensed by the bus thermostat
Functions
Real-time clock
Built-in RTC with battery backup; time is retained through power loss, enabling scheduled scenes, night mode and time-based energy saving
Configuration storage
Configuration and scenes stored locally, retained through power loss
Lighting scenes
Multiple scenes, editable on site
Occupancy detection
Card holder, cardless detection (door contact + PIR), or both
Local configuration
DIP switch, web interface, or PC configuration software
Firmware upgrade
Local, via PC software, or remote OTA
HVAC control (via bus devices)
Chilled-water fan coil
The fan coil unit is wired directly to the GLMZK bus thermostat (6 wires for a single-valve / 2-pipe system, 7 wires for a two-valve / 4-pipe system, including neutral and earth). The thermostat connects to the RCU over RS485 for central control. A 4-relay version covers 3 fan speeds plus one valve; a 5-relay version covers 3 fan speeds plus heating and cooling valves.
VRF / DX systems
Controlled by an IR repeater reproducing the original remote-control codes, connected to the RCU over RS485. The IR code library covers the majority of brands on the market; on/off, mode, fan speed and setpoint are supported.
Local control retention
The thermostat retains full local control if the bus or the central system is unavailable
Mechanical and wiring
Mains-side terminals
Barrier terminal blocks, 9.52 mm pitch, each position accepting up to 2 × 2.5 mm² conductors
Dimming group terminal
7 positions per group: 1 supply negative, 2 supply positive (common anode) and 4 dimming outputs
Relay output terminal
6 positions: 4 switched live outputs plus N and L (230 V AC supply; L is the relay common and also feeds the mains-detection circuit)
Low-voltage terminals
Pluggable terminal blocks, 5.08 mm pitch: 2 × 8-position (signal inputs) and 2 × 4-position (RS485)
Segregation
Mains-side and low-voltage terminals are located on opposite sides of the unit
Indicators
On-board LED indicator for every relay and dimming circuit
Load neutrals
Load neutrals connect to the building neutral bar, not to the RCU
Full terminal assignment, the door-display RJ45 pin-out and the outline drawing are given in the
downloadable specification sheet. A DXF version of the outline drawing is available on request.
Scope of supply
Supplied with the system
RCU GLMZK-TG120 · switch and control panels · bus thermostat (4- or 5-relay version) · IR repeater for VRF systems · door display panel · card holder and occupancy devices · 24 V / 400 W power supply
To be provided locally
AC contactor for the socket circuits · 24 V LED luminaires · cabling, conduit and circuit breakers · one network switch port per RCU · back boxes if sourced locally · installation labour and commissioning on site
Important installation notes
Power input 1 also supplies the RCU control circuit and must always be connected.
The door-display port and the network port use identical RJ45 connectors but are not interchangeable. Connect according to the labelling on the housing.
Dimming outputs are for 24 V DC constant-voltage LED luminaires only. 230 V AC luminaires must be connected to the relay circuits.
Refrigerators, minibars, safes and network equipment must be fed from an uncontrolled circuit, not from the contactor-switched socket circuit.
Mechanical dimensions in this revision refer to the current hardware (Rev. A). Please confirm before finalising enclosure or panel design.
Frequently asked questions
Does the GLMZK-TG120 need an internet connection to work?
No. The RCU operates fully standalone. Lighting, scenes, occupancy logic, scheduled events and HVAC control all continue to work with no network and no cloud service. The Ethernet port is used for remote commissioning, diagnostics and central management.
Is a separate gateway required for each room?
No. The network gateway function is built into every GLMZK-TG120. One RCU per room is one gateway per room; no additional gateway hardware is needed.
Can the system be integrated with a hotel PMS or third-party system?
Yes. GLMZK supplies the interface and documentation so that the hotel’s own IT team or integrator can carry out the PMS integration. The interface is quoted separately from the hardware. Please state which PMS and which integration method you require.
Is GLMZK a factory or a trading company?
GLMZK is a manufacturer. Shenzhen GLMZK Intelligent Electric Co., Ltd. has produced hotel guest room control systems since 2009, with products installed in over 1,000 hotels and more than 30,000 guest rooms.
What is the certification status?
CE assessment under EMC 2014/30/EU and LVD 2014/35/EU has not yet been completed for this model, and it can be arranged for project supply — please enquire for the current status and timescale. RoHS testing has not yet been carried out and can likewise be arranged. The relays used in the unit are UL, TÜV and CQC certified components; component certification does not constitute certification of the complete unit.
What is the OEM minimum order quantity and the lead time?
There is no fixed minimum order quantity. The GLMZK-TG120 is a customised product, so each project is quoted on its own configuration, and sample or mock-up room quantities are accepted. Lead time is 30 working days after order confirmation. OEM customisation covers housing labelling, panel engraving, firmware behaviour and packaging — contact us with your project details.
Which luminaires can be dimmed?
24 V DC constant-voltage LED luminaires without an integrated driver — LED strip, and 24 V integrated LED downlights and spotlights. 230 V AC luminaires, including GU10 and E27/E14 lamps, cannot be dimmed by this unit and are switched by the relay outputs instead.
Can one RCU cover a suite or a large room?
One unit provides 8 dimming channels and 4 relay circuits. Where more circuits are required, additional RCUs can be used in the same room, or circuits can be combined. Send us your lighting circuit list and we will confirm the configuration.
Request a quotation or a sample
Shenzhen GLMZK Intelligent Electric Co., Ltd. — Shenzhen, China
Email: sales@smartguestroom.com ·
Tel: +86 755 2150 4866 · WhatsApp: +86 135 9031 0613
Tell us the number of rooms, the lighting circuit list and the HVAC type, and we will return a
configuration list and a quotation.
