Round Rocker Switch KCD1-105
Switches and sprayers · 1 option in stock
Machine switches and coolant sprayers — buttons, selector switches, emergency stops and mist units. The parameters are listed in order of importance: the one at the top decides the most, and no amount of care further down makes up for getting it wrong.
This page lists 1 option, from ¥0.3.
What this part is
KCD1-105 round rocker switch, two pins, latching or momentary, clipping into a 20 mm round panel hole. Main power or a function switch on a piece of equipment.
The parts of this item
Figure 1 — Switches are about hole size and contacts, mist units about orifice and port — both speak in holes
The parameters that matter
Not every number on a part like this is worth the same. These are the ones that decide whether it fits and works, and what to look at for each.
| Parameter | What to check |
|---|---|
| Poles | Two pins (SPST). It breaks one line only, not live and neutral together — worth remembering on mains. |
| Rating | Usually 10 A / 250 VAC. Derate for inductive motor loads: inrush can be five to eight times rated. |
| Cutout | Φ20 mm. Too big and it will not clip in, too small and it will not go in. |
| Action | Latching (press on, press off) or momentary (on while held). The suffix differs between them. |
Reading the part numbers
| Part no. | Configuration |
|---|---|
EG-090 | single configuration |
You can order by part number or by selecting the parameters. The part number is fastest, but it does not always encode every parameter — the selector on this page is the authority.
6 common mistakes
- Contact rating is the one that fails silently. The switch works for a week, then the contacts stick closed and the machine will not stop.
- Normally open and normally closed are different parts. Wire it the other way and the logic is inverted — the limit triggers at the wrong end.
- An emergency stop must latch. A momentary button is not an emergency stop, whatever the label says.
- Check the panel thickness. The thread length limits how thick the panel can be.
- Measure before you order. Take the old part off and measure it, or send us a photo with the caliper reading — that beats guessing from a model number every time.
- Everything here is in millimetres. Where a size is imperial, convert it: 1" = 25.4 mm, 1/4" = 6.35 mm, 3/32" = 2.38 mm.
Telling it apart from lookalikes
Against a KCD1-101 rectangular rocker: the 101 needs a rectangular cutout, the 105 a round one. Electrically identical — only the panel hole differs.
Confirming it is the right part
This page has one configuration, so there is nothing to choose — which makes confirming that it is the right part more important than studying the specification. Three steps is enough:
- Measure the mating dimension — the one place this part touches something else: bore, shaft, thread, tube OD, or hex across flats. It is the number people get wrong, and half a millimetre out means it will not fit.
- Measure the outline and the mounting hole spacing. Two parts that do the same job from two makers often differ by 2–3 mm between holes: it looks like it will fit, and it goes on crooked.
- Send us two photographs: one general view showing the machine and where the part sits, and one close-up with the caliper reading in shot. If the machine has a nameplate, include it — plenty of these parts are specific to one machine, and the model number locates them faster than dimensions do.
When to replace it
You do not replace this until it fails — but "still looks usable" and "still reliable" are two different things. Any one of these and it is time:
- Contacts stuck closed, or the button no longer springs back.
- The actuation point has drifted, or it only works when pressed hard.
Fitting and use
Before wiring
- Confirm voltage and polarity first. Reversed, it is destroyed on the first switch-on — there is no second chance. DC parts especially.
- Wire with the power off, then check continuity and insulation with a meter before you apply power.
- Crimp or tin the wire ends. Twisting bare strands onto a terminal gives a high-resistance joint that heats up.
Mounting
- Leave the heated parts some air. Do not mount them against plastic or against the cable run.
- Parts with a direction (fans, check valves) have an arrow. Reversed, you lose most of the airflow or flow.
- Fasten it properly. Vibration loosens terminals, and loose terminals are the most common electrical failure there is.
First power-up
- First power-up from a current-limited supply, or through a fuse. If something is wrong the damage stays small.
- Run it unloaded first, measure current and temperature, then add load.
- After 30 minutes feel the terminals and the cable. Anything noticeably warm means high contact resistance — re-crimp it.
Three things not to do
- Do not connect or disconnect under power unless it is explicitly rated for hot-plug. The arc damages the terminals.
- Do not run above the rating. It works for a while, then it does not.
- Do not skip the earth or the fuse. You save a few yuan and risk the machine.
Matching parts
- Wire and ferrules
- Terminals and heat shrink
Lead time, custom work and shipping
- Stock sizes: dispatched in 1–2 working days, subject to stock
- Custom: non-standard sizes, materials and treatments are possible — send quantity and drawing
- Shipping: from Shenzhen; domestic courier by default, DHL or dedicated line for export
- Volume: quantity pricing available, contact us for a quote
If you cannot find the size you need, or you are not sure which one fits, send us the problem you are solving — what machine it goes on, the dimensions of the part you have, what it has to achieve — and we will match it.