EN
Panel indicator lights are simple components, but they play an important role in equipment operation.
They help operators understand whether a system is powered, running, ready, stopped, or in a warning condition.
A poorly selected indicator may be difficult to see, use the wrong voltage, create confusing color logic, or fail under environmental exposure.
The correct choice should consider both electrical and visual requirements.
1. Define the Status to Be Displayed
The first step is to decide what the indicator light represents.
Common functions include:
• Power available
• Equipment running
• System ready
• Warning
• Fault
• Charging
• Heating
• Cooling
• Pump operation
• Motor operation
• Door position
• Hydraulic condition
• Communication status
The indicator should represent a clear and useful equipment state.
Too many lights can make a panel confusing.
Each indicator should have a defined meaning.
2. Select the Mounting Size
Common panel indicator sizes may include:
• 6mm
• 8mm
• 10mm
• 12mm
• 16mm
• 19mm
• 22mm
The available sizes depend on the product series.
Smaller lights are suitable for compact panels and dense indicator groups.
Larger lights provide stronger visibility and may be easier to recognize from a distance.
The exact panel cutout, thread size, body depth, and nut dimensions should be confirmed from the drawing.
3. Confirm the Operating Voltage
The indicator voltage must match the equipment power supply.
Possible applications may use:
• 2.4V
• 5V
• 6V
• 12V
• 24V
• 36V
• 48V
• 110V
• 220V
• Other customized voltages
The available range depends on the specific indicator structure.
The customer should confirm:
• Supply voltage
• AC or DC
• Voltage tolerance
• Continuous operation
• Internal resistor
• Polarity
• Current consumption
A low-voltage LED cannot be connected directly to a higher voltage without a suitable resistor or internal circuit.
4. Understand AC and DC Requirements
Some indicator lights support both AC and DC, while others are designed for a specific supply type.
For DC circuits, polarity may matter.
The positive and negative terminals must be connected correctly unless the product includes a non-polarized internal design.
For AC circuits, the internal resistor or circuit must be suitable for the specified voltage.
The voltage marking should always be checked before installation.
5. Choose the LED Color
Common LED colors include:
• Red
• Green
• Blue
• Yellow
• White
• Orange, depending on the series
Color should communicate a consistent meaning.
Typical uses include:
Red
• Fault
• Stop
• Alarm
• Critical warning
• Unsafe condition
Green
• Running
• Ready
• Normal status
• Available
• Successful operation
Yellow
• Caution
• Attention
• Waiting
• Intermediate condition
Blue
• Special mode
• User-defined function
• Auxiliary system
White
• General status
• Lighting
• Neutral indication
• System availability
Orange
• Warning
• Heating
• Transitional status
• Equipment-specific function
The final color logic should follow the equipment design and applicable market requirements.
6. Consider Brightness and Viewing Conditions
An indicator must be visible under the actual operating conditions.
Important factors include:
• Indoor or outdoor use
• Direct sunlight
• Night operation
• Viewing distance
• Viewing angle
• Panel color
• Operator position
• Cabin lighting
• Nearby illuminated controls
An indicator that looks bright indoors may be difficult to see in direct sunlight.
An overly bright indicator may cause glare during night operation.
For equipment used in both day and night conditions, sample testing is recommended.
7. Select the Head Style
Indicator lights may use different lens or head designs.
Common options include:
• Flat head
• Domed head
• Raised head
• Flush head
• Diffused lens
• Clear lens
• Colored lens
• Symbol or customized marking
Flat or Flush Head
Provides a clean panel surface and may reduce accidental impact.
Domed or Raised Head
Offers a larger visible area and can be easier to identify from different angles.
Diffused Lens
Spreads the light more evenly and reduces a concentrated bright point.
Clear Lens
Can create stronger direct brightness but may have a narrower viewing effect.
The head style should be selected based on visibility, panel appearance, and exposure risk.
8. Choose the Housing Material
Indicator light housings may use:
• Plastic
• Metal
• Brass components
• Stainless steel exterior options
• Plated metal finishes
Plastic housings can provide electrical insulation and lower weight.
Metal housings provide a different appearance and may offer better mechanical protection in some panel designs.
Stainless steel options may be suitable where corrosion resistance, cleaning, or appearance is important.
The exact material should be confirmed instead of using a general “metal” description.
9. Evaluate Environmental Protection
Indicator lights installed on outdoor machinery, vehicles, marine panels, and exposed control boxes may require front-panel sealing.
Important points include:
• IP rating
• Protected area
• Sealing washer
• Mounting hole
• Panel surface
• Nut tightening
• Rear wiring protection
IP67 front-panel sealing normally protects the portion above the panel when installed correctly.
It does not automatically protect the rear terminals or wires.
Where the rear is exposed, a sealed wire-lead structure may be required.
10. Choose the Connection Type
Common connection methods include:
• Solder terminals
• Wire leads
• Quick-connect terminals
• Pin terminals
• Customized connectors
Solder terminals provide compact installation.
Wire leads reduce customer assembly steps and can support customized length and connectors.
Quick-connect terminals support fast installation and replacement.
The correct option depends on:
• Production volume
• Rear-panel space
• Maintenance
• Environmental exposure
• Wiring harness design
• Current and voltage
11. Check Wire Specifications
For wire-lead indicators, confirm:
• Wire gauge
• Wire length
• Insulation
• Color
• Stripping length
• Connector
• Polarity marking
The wire colors should clearly identify positive and negative connections in DC applications.
For high-voltage versions, insulation and spacing requirements must be appropriate.
12. Single-Color, Dual-Color, and Multi-Color Indicators
Some indicator designs can provide more than one color.
A dual-color or multi-color indicator may reduce the number of panel openings.
For example, one indicator could show:
• Green for normal
• Red for fault
However, the wiring becomes more complex.
The equipment manufacturer should confirm:
• Number of terminals
• Common positive or common negative
• Available colors
• Operating voltage
• Simultaneous lighting
• Color mixing
• Control logic
Multi-color indicators should only be used where the meaning remains clear.
13. Separate Indicator Light or Illuminated Button?
An illuminated push button combines control and indication.
A separate indicator light only displays status.
A separate indicator may be better when:
• The equipment status must remain visible at all times
• The indication is independent of a control button
• The operator must monitor the status from a distance
• Multiple conditions are grouped in one location
• The control is located elsewhere
An illuminated button may be better when the control and status are closely related and panel space is limited.
14. Electrical Isolation from the Control Circuit
The indicator circuit should be designed separately from the controlled load when required.
For example, an indicator showing “motor running” should ideally receive a signal representing actual motor operation.
It should not always be connected only to the switch output.
Otherwise, the light may indicate that the command was given even if the motor failed to start.
The most useful indicator displays the real equipment condition.
15. Power Consumption
LED indicators generally consume little power, but total consumption can matter when many lights are installed.
This is especially relevant for:
• Battery-powered equipment
• Mobile vehicles
• Standby systems
• Low-power electronics
• Solar-powered equipment
The current consumption of each indicator should be checked.
16. Temperature and Service Life
LED performance can be affected by:
• High temperature
• Low temperature
• Voltage variation
• Continuous operation
• Vibration
• Moisture
• Poor heat dissipation
The operating temperature should match the equipment environment.
Brightness and color may change under extreme conditions.
For long-term equipment, LED life and replacement method should also be considered.
17. Panel Labeling
Color alone should not always be the only method used to communicate status.
Labels, symbols, or text can improve clarity.
This is particularly important for:
• International users
• Color-vision differences
• Complex panels
• Emergency functions
• Multiple similar indicators
A clear label helps prevent operator misunderstanding.
18. Sample Testing
Before volume production, test indicator lights for:
• Panel fit
• Brightness
• Viewing angle
• Daylight visibility
• Night glare
• Color meaning
• Voltage compatibility
• Polarity
• Wire length
• Sealing
• Vibration
• Heat
• Operator understanding
The visual result should be evaluated on the actual equipment panel.
Common Selection Mistakes
Selecting Only by Color
Voltage, mounting size, visibility, and wiring must also be confirmed.
Using the Wrong Voltage
This may damage the LED or create weak illumination.
Ignoring Polarity
DC indicators may not light if connected in reverse.
Assuming IP67 Means Fully Waterproof
The rating may apply only to the front panel.
Using One Color for Multiple Meanings
This can confuse operators.
Choosing a Light That Is Too Bright or Too Dim
Actual day and night conditions should be tested.
Questions to Confirm Before Ordering
1.What condition will the light indicate?
2.What mounting size is available?
3.What is the supply voltage?
4.Is the supply AC or DC?
5.What LED color is required?
6.Is polarity important?
7.Will the equipment operate outdoors?
8.Is IP67 front-panel sealing required?
9.Is wire or terminal connection preferred?
10.What wire length and connector are needed?
11.Is single-color or dual-color indication required?
12.What viewing distance is expected?
Conclusion
A panel indicator light should provide clear, reliable, and easily understood equipment status.
The correct selection depends on mounting size, voltage, AC or DC supply, LED color, brightness, head style, housing, connection method, sealing, and operator viewing conditions.
TOOWEI offers panel indicator lights in multiple sizes, colors, voltages, head styles, housing options, and wiring configurations for equipment control panels, vehicles, machinery, and OEM systems.
CTA
Send TOOWEI your mounting size, supply voltage, LED color, head style, wire requirements, sealing level, and equipment application for product selection support.