IMF21 inductive square type proximity sensor PNP NPN

Q: What is the difference between a contactor and a relay?

A contactor is built for switching power circuits repeatedly at high current, often with motor duty ratings (AC-3) and arc-suppressing chambers. A relay switches control signals at low current. In practice: contactor for the motor, relay in the control circuit that drives the contactor coil.

Q: How do I calculate the correct contactor size for a motor?

Use the motor's full-load current, apply the AC-3 rating for the operating voltage, and allow for the number of starts per hour. As a rule of thumb, the contactor's AC-3 rating should be at least equal to the motor FLC, then step up one frame if the duty is heavy.

Q: Do you supply the coil voltage I need?

Coil voltages are specified per order. Send the model number, coil voltage and frequency you require and we will confirm availability and lead time.

Q: Are auxiliary contacts included?

Base models come with the standard auxiliary contact configuration for that frame. Add-on auxiliary blocks and mechanical interlocks can be quoted with the contactor.

About the IMF21 inductive square type proximity sensor PNP NPN

The IMF21 inductive square type proximity sensor PNP NPN is part of the ELEHPD Square Inductive Type range. IMF21 inductive square type proximity sensor PNP NPN from the ELEHPD Square Inductive Type range. ELEHPD manufactures and exports low voltage electrical products from Yueqing, Zhejiang, China, supplying distributors, panel builders, M&E contractors and OEM buyers worldwide.

Full catalogue description: inductive square type proximity sensor PNP NPN switch IMF21

Typical applications

Motor control centres and pump or fan starters
Machine building, conveyors, packaging and CNC equipment
HVAC control panels and building automation
Water treatment, irrigation and pumping stations
Panel retrofits replacing electromechanical control gear

How to specify the right Square Inductive Type

Size the contact rating for the inductive load, not just the resistive current (AC-3 duty for motors)
Check the coil voltage and frequency available in the panel: 24 V DC, 110 V, 230 V or 400 V AC
Confirm the auxiliary contact count needed for the control and indication circuit
Match the enclosure rating to the environment (IP20 inside a panel, IP65 on the machine)

Specifications

inductive square type proximity sensor PNP NPN switch IMF21

外形尺寸 OVERALL DIMENSIONS
	检测距离 DETECTION DISTANCE 4mm
埋入式 F l u s h	直流 DC 10- 30 VDC 交流 AC 90- 250 VAC	NPN	NO
NC
NO+NC
PNP	NO
NC
NO+NC
二线制 two wire system	NO
NC
SCR 可控硅 Control- lable silicon	NO
NC
NO+NC
继电器输出Relay output
	检测距离 DETECTION DISTANCE 4mm
非埋入式 F l u s h	直流 DC 10- 30 VDC 交流 AC 90- 250 VAC	NPN	NO	IMF21-4-DNA
NC	IMF21-4-DNB
NO+NC	IMF21-4-DNC
PNP	NO	IMF21-4-DPA
NC	IMF21-4-DPB
NO+NC	IMF21-4-DPC
二线制 two wire system	NO	IMF21-4-DLA
NC	IMF21-4-DLB
SCR 可控硅 Control- lable silicon	NO
NC
NO+NC
继电器输出Relay output
输出电流 Controloutput	DC	200mA
SCR/继电器 Relay
输出电压降Output voltagc dropDC/AC	直流(NPN PNP)型3V以下、二线型：3.9V以下、交流AC 10V以下 DC<3V、AC<10V
消耗电流Consumption current	直流(NPN PNP)型DC 12V时8mA、24V时15mA、交流AC 10mA以下DC<15mA、AC<10mA
标准检测物体Standard detected object	12X12X1(A3铁iron)
重复精度Repeated precision	0.01
响应频率DC/AC	500Hz/5Hz
工作环境温度Working environment temperature	-25℃～+70℃
绝缘电阻Insulation resistance	50MΩ
外壳材料Shell material
防护等级Protection grade	IP67
可替代国内型号Altemative model at home and abroad

Frequently asked questions about the IMF21 inductive square type proximity sensor PNP NPN

What is the difference between a contactor and a relay?