XL-21 Power Distribution Cabinet

Wall-Mount | Floor-Standing | Motor Control | Lighting Distribution

What This Cabinet Actually Is

The XL-21 is a floor-standing or wall-mounted power distribution cabinet designed for motor control, lighting distribution, and small-scale power management in industrial and commercial environments. It sits one tier below GGD in complexity and one tier above a simple junction box in capability.

If GGD is the main distribution board for a building or substation, XL-21 is what you install next to a pump, a conveyor, an HVAC unit, or a production line to switch, protect, and control that specific load.

It is not a switchgear assembly in the IEC 60439 sense. It is a functional enclosure - a steel box with a door, a back plate or DIN rail, and enough internal space for breakers, contactors, relays, and terminal blocks to do a specific job.

Where It Goes

Application	Typical Configuration	Why XL-21 Fits
Motor Control Center (small)	Isolator + MCCB + contactor + thermal relay + pushbutton	Compact, front-access, component visibility
Lighting Distribution Board	Main breaker + 6–12 outgoing MCBs + timer or photocell	DIN rail mounting, easy wiring access
HVAC Control Panel	Main isolator + contactors + thermostats + fan speed controllers	Ventilation slots standard, IP54 option for humidity
Pump Station Control	Float switch input + contactor + overload + hour meter	Simple logic, robust enclosure, outdoor option
Production Line Feeder	Main breaker + multiple motor starters + emergency stop circuit	Component density, door-mounted controls
Generator Set Control	ATS controller + breakers + meters + alarm outputs	Standard cutouts for HMI and indicator lamps

The Physical Reality

Envelope Dimensions

Model	Width (mm)	Height (mm)	Depth (mm)	Mounting
XL-21-4	400	500	200	Wall
XL-21-5	500	600	250	Wall / Floor
XL-21-6	600	800	300	Floor
XL-21-8	800	1000	350	Floor
XL-21-10	1000	1200	400	Floor

Custom dimensions available. The "standard" sizes above reflect what we stock as blank enclosures. Non-standard sizes add 3–5 days for sheet metal work.

Construction

Element	Specification	Notes
Enclosure	Cold-rolled steel, 1.2–2.0mm	1.2mm for wall-mount, 2.0mm for floor-standing
Door	Single or double, hinged right	Reversible hinge on request
Back plate	Galvanized steel, 1.5mm	Pre-drilled for component mounting
DIN rail	35mm standard, 7.5mm height	Pre-installed, length per model
Cable entry	Top and bottom knockouts	Ø20–Ø50mm standard, gland plate optional
Ventilation	Louvered slots, top and bottom	IP30 standard; sealed for IP54
Finish	Powder coat, RAL 7035 (light gray)	RAL match available
Lock	Quarter-turn cam lock, 8mm double-bit	Padlock hasp optional

Component Mounting Capacity

Component Type	Width per Unit	Max Count	Notes
Miniature Circuit Breaker (MCB)	18mm (1P) / 36mm (2P) / 54mm (3P)	24 / 12 / 8	1P modules, single-phase distribution
AC Contactor	45mm (up to 32A) / 90mm (up to 95A)	10 / 5	Standard IEC contactors
Thermal Relay	45mm	10	Direct-mount below contactor
Timer Relay	35mm (DIN rail)	12	Multi-function or delay types
Indicator Lamp	22mm (panel mount)	20	Door-mounted
Pushbutton	22mm (panel mount)	12	Door-mounted, start/stop/reset
Terminal Block	6–10mm	60+	Depending on current rating
Current Transformer	60–100mm	3	Panel-mounted for metering

Rule of thumb: If you need more than 12 motor starters or more than 24 outgoing feeders, you have outgrown XL-21 and should consider GGD or GCK.

Protection Ratings

IP Code	Construction Change	Application
IP30	Standard louvered ventilation slots	Indoor, clean environment, general industrial
IP40	Fine mesh over ventilation slots	Indoor, dust-sensitive areas
IP54	Sealed gasket on door, no ventilation slots, internal fan optional	Outdoor, rain exposure, washdown areas
IP65	Full gasket seal, no ventilation, cable glands mandatory	Heavy washdown, marine, chemical

Thermal note: IP54 and IP65 enclosures require derating or forced ventilation if internal heat dissipation exceeds 200W. We calculate this based on your component list and recommend fan size or external heat sink if needed.

Electrical Specifications

Parameter	Range	Notes
Rated voltage	AC 220V / 380V / 415V	Single-phase or three-phase
Rated current	Up to 630A (main incoming)	Higher on request with busbar upgrade
Short-circuit withstand	Up to 50kA	Depends on breaker specification
Frequency	50Hz / 60Hz	Standard
Control voltage	AC 220V / AC 380V / DC 24V	Specified per project
Busbar material	Copper or aluminum	Copper standard; aluminum for cost reduction
Busbar rating	100A – 630A	Sized to incoming breaker
Earth bar	Copper, full length of cabinet	Mandatory, per IEC 60439

Customization Options

Standard (No Additional Cost)

Option	Description
Door configuration	Single door, double door, or no door (open frame)
Mounting	Wall brackets, floor plinth, or free-standing
Cable entry	Top, bottom, or both; knockout or gland plate
Internal layout	Back plate only, DIN rail only, or mixed
Color	Any RAL color (standard is RAL 7035)
Labeling	Component labels, warning signs, circuit directory

Engineered (Additional Cost)

Option	Description
Cutouts	HMI display, meter windows, ventilation fans, cable glands
Internal partitions	Separate compartments for power and control
Busbar extension	Vertical or horizontal busbar for multi-cabinet arrays
Insulation monitoring	Built-in insulation resistance meter
Heater and thermostat	Anti-condensation for outdoor or humid environments
Internal lighting	LED lamp with door switch
Document pocket	A4 size, door-mounted

How to Specify One

Send us:

Load list - What motors, what power, what voltage, what starting method (DOL, star-delta, soft starter, VFD)

Control requirements - What switches, what indicators, what interlocks, what sequence

Environmental conditions - Indoor/outdoor, temperature range, humidity, dust, chemicals

Integration points - What connects to what upstream and downstream

Standards and certifications - IEC, UL, CSA, local utility requirements

We return:

Single-line diagram

Component layout drawing

Bill of materials with brand options

Quotation with lead time

Lead Time

Configuration	Quantity	Lead Time
Standard enclosure, no assembly	1–50	5–7 working days
Standard enclosure with standard components	1–10	10–15 working days
Custom enclosure with standard components	1–10	15–20 working days
Custom enclosure with custom logic	1–5	20–25 working days
Large project, phased delivery	50+	Confirm with project manager

Standards & Compliance

GB7251.3-2006 - Low-voltage switchgear and controlgear assemblies (Chinese standard for distribution boards)

IEC 60439-3 - International equivalent for distribution boards

IP testing - In-house or third-party per IEC 60529

Material certification - Mill test reports for steel and copper

XL-21 vs. Other Cabinet Types

	XL-21	GGD	GCK/GCS	Custom Panel
Typical current	≤630A	≤3150A	≤3150A	Any
Typical function	Motor control, lighting	Main distribution	Motor control center	Special purpose
Mounting	Wall or floor	Floor only	Floor only	Any
Withdrawable units	No	No	Yes	Optional
Internal busbar	Simple	Extensive	Extensive	Custom
Cost	Low	Medium	High	Variable
Lead time	10–15 days	15–20 days	25–35 days	20–40 days