LED switching lamps — SKL
SKL - LED switching lamps replace the incandescent switching lamps traditionally used in switchgear and in prefab one-way cameras as indicators.
Lamps like KM 24-50 or KM 60-50 are becoming a thing of the past, giving way to more economical LED lamps that look almost the same and perform the same functions - switch position indication, automation status signaling, etc. The marking of signal lamps is simple: KM-switch room, the first number is the supply voltage in volts, the second is the current consumption of the lamp in milliamps. LED analogs are marked differently, but more on that later.
KM lamps have always had a traditional T 6.8 brass base covering an elongated evacuated glass envelope and a characteristic plastic cap.
The design of the lamp and spiral makes the product as a whole quite durable, relatively shockproof, vibrationproof, specially adapted for horizontal working position and guaranteed to work for at least 3000 hours.
The installed light looks simple — like a glowing eye under the corresponding color filter: the high voltage power switch is on — the red indicator is on, the switch is off — the green is on.
A typical power supply circuit for a switching lamp is in series through a powerful additional resistor of a few kilo-ohm ratings from the corresponding circuit. For example, a protective relay will be triggered — the yellow flashing light will light up. By the way, despite the «vibration-resistant» bulb and base, the conventional KM lamp with a spiral still breaks down quite early due to regular frequent switching, on-off-the spiral eventually burns out. So they are everywhere replacing switching lamps with spirals with LEDs.
This table gives an explanation of the LED switch lamp markings:
The symbol structure of SKL lamps
The user will only have to select a suitable lamp from the manufacturer's catalog and install it in place of the previous one. It is also possible to choose the type of contacts for connecting wires - for soldering or screw. The dimensions of the mounting hole are selected based on the parameters of the existing signal fittings, and the direct attachment to the shield is done with a plastic clamping nut supplied with the LED lamp.
No additional resistors are needed here! Agree, there is a reason when there are no bulky heating parts that dissipate excess heat, take up space, threaten to crack, ultimately — create a fire hazard. LEDs don't get as hot as filaments...
Now for the merits. SKL lamps have a degree of protection IP54 at operating temperatures from -40 ° C to + 60 ° C.Current consumption is in units of milliamps. The widest range of nominal supply voltages is available — from 6 to 380 volts. The absence of a filament as such makes SKL LED switching lamps truly shockproof and vibrationproof, therefore they last much longer than the previous 3000 hours, here the service life is measured in tens of thousands of hours (up to 50,000 hours).