Nakakita NS286

磁性浮子液位开关

Nakakita magnetic float level switches for tank and bilge-well level alarms (lube oil sump and gravity tanks, bilge wells, etc.). A float on a stem moves an iron core inside a sealed tube; a magnet outside follows it and actuates a micro switch (SPDT). The manual has one specification sheet per tag (service, fluid, specific gravity, set levels, action high/low), drawings, and instructions to adjust the on-off differential, the magnet stroke and micro-switch operating point, the operating level, installation, wiring, specific-gravity compensation and maintenance. Bilge-well switches work through intrinsically safe switch-operated relays.

点击模型上的零件，查看编号和用途。打开 3D 说明书

保养规程

Adjusting the micro switch

1. Turn the switch adjust screw so that the magnet holder rests 3.8 mm from its attraction position (free position). 第 76 页
2. Set the switch operating screw so the micro switch changes over 2.3 mm from the free position. 第 76 页
3. For two-switch units insert a 1.5 ± 0.1 mm gauge so the magnet cannot touch the pipe, then set No.1 and No.2 switches with a circuit tester so both actuate together. 第 87 页
4. Lock the screws with red lock paint. 第 88 页

Changing the operating level

1. Turn the knob to move the whole switch unit up or down within the ±10 mm scale. 第 88 页
2. For larger changes move the upper or lower limit float on the stem, measuring from the flange face to the level band. 第 88 页

Yearly check

1. Switch off the power, measure insulation resistance. 第 94 页
2. Test with water and confirm actuation; remember the mark is for the design specific gravity, so with water it actuates lower. 第 94 页
3. If the point deviates more than 5 mm, open it, wipe deposits off the tube and iron core and reassemble with match marks. 第 94 页

保养周期

项目	周期	操作	说明书
Each level switch	every year	Independent function test; clean tube and iron core if the actuation point has drifted more than 5 mm	第 94 页

故障及处理方法

Actuation point drifts or switch sticksDeposits on the tube inner wall or iron core from dirty liquidMagnet does not release from the tubeContact resetting spring weak

技术参数

Body / float material	SS400 body, SUS304 float (typical sheet)	第 3 页
Contact	SPDT micro switch, AC 250 V 5 A / DC 250 V 0.3 A resistive	第 3 页
Insulation test	DC 500 V megger, over 100 MΩ	第 3 页
Withstand voltage	AC 1500 V for 1 minute	第 3 页
Set level accuracy	±10 mm on sheet; setting precision within ±5 mm	第 89 页
On-off differential	about 10–30 mm standard; adjustable ±25 mm by range plates	第 66 页
Magnet free position	3.8 mm from attraction position	第 76 页
Micro switch operating point	2.3 mm from free position; differential 0.2–0.7 mm	第 76 页
Operating level change	±10 mm by the knob on the switch	第 86 页

来源：制造商说明书《EM-36 LEVEL SWITCH》，共 95 页。页码以原文为准。作业前请核对船上的说明书。

本页为自动翻译。零件号、代码和页码与原文一致。