22mm Deca Pilot Lights & Indicator Lamps by Color and Voltage (12V/24V/110V)

What a pilot lamp does and how these work

A pilot lamp shows when an electrical circuit is closed and energized. It's a status indicator, not a control device. Wire it to the point you want to monitor and it lights when that point is powered.

These Deca A20P-1BEQ lamps use a single fixed-voltage LED rated 50,000 hours, illuminating a marking-plate lens through the 22 mm head. Current draw is low: 0.013–0.014 A at 12V/24V and 0.0055 A at 110V, so the supply carries almost no extra burden. Because they're AC/DC rated, the same 24V unit works on 24VDC logic power or a 24VAC control transformer.

The body measures 26.5 x 30 x 33.7 mm (1.04" x 1.18" x 1.32"). Dielectric strength is 2000V AC for one minute on the illuminated unit and 2500V AC on the contact block, with 100 MOhm insulation resistance at 500VDC.

How to choose pilot lamp color by IEC convention

Color communicates machine state to the operator. Follow the IEC 60204-1 indicator convention so anyone can read your panel:

• Red: emergency, fault, hazardous or energized condition requiring immediate action
• Green: normal, running, ready, safe
• Yellow: warning, caution, abnormal condition, impending change
• Blue: mandatory action required, or a forced/specific condition
• White: power on, general status, no specific meaning assigned

All five colors are available in 12V (A20P-1BEQ3* series) and 24V (A20P-1BEQ4* series). At 110V, only green (A20P-1BEQHG) and blue (A20P-1BEQHS) are offered. Choose the color for the meaning, confirm the voltage suffix, and you have the part number: suffix 3 = 12V, 4 = 24V, H = 110V; last letter R/G/Y/S/W = red/green/yellow/blue/white.

Matching lamp voltage to your control circuit

The single most important check is voltage. Each LED is engineered for one nominal voltage and is not a wide-range unit.

• Use 12V (A20P-1BEQ3*) only where 12V AC or DC is present
• Use 24V (A20P-1BEQ4*) for the majority of PLC and relay panels running 24VDC control power or 24VAC transformers
• Use 110V (A20P-1BEQH*) for 100–120VAC control circuits

Underpowering (feeding a 24V lamp with 12V) leaves it dim or dark. Overpowering (24V or 110V into a 12V lamp) burns out the LED, sometimes instantly. If your panel runs 120VAC but you need red, yellow, or white (colors not stocked at 110V), they can be special ordered. Verify your actual measured voltage before ordering, not just the nameplate.

Installing a 22 mm pilot lamp in a panel

Installation is straightforward with the right cutout and clearance. Always de-energize and lock out the panel before wiring:

• Confirm a clean 22 mm mounting hole; deburr the edge so the seal seats flat
• Check depth: the body is 33.7 mm deep, plus room for terminals and wire behind the panel
• Insert the head from the front, then thread the mounting collar from behind and snug it by hand
• Land your two wires on the illuminated-unit terminals; follow the labeled markings. DC LED units are polarity-sensitive, AC units are not
• For IP 65 integrity at the panel face, ensure the front gasket sits flat against the panel

Keep leads away from high-current conductors and protect the circuit per your panel schematic and NEC/local code. Operating temperature range is -25°C to 55°C; storage tolerates -45°C to 85°C. After power-up, verify the correct color illuminates at full brightness. A dim lamp usually means a voltage mismatch.