Sensor

1) Overview

The crane sensor is a key component used to detect and monitor the operating status of the crane, so as to ensure the safe and efficient operation of crane.

CTECH Machinery Sdn Bhd specially produces limit switches that achieve precise positioning of cranes and improve operational accuracy.

2) Basic types

1) Limit switch: the trolley’ track and lifting structure of overhead crane

*Limit switch for electric hoist wire rope

*Limit switch for the slewing or drive shaft of cranes

*Limit switch via utilizing optoelectronic, inductive, capacitive, or microprocessor technologies

2) Ultrasonic sensor: surrounding of overhead crane

3) Infrared sensor: surrounding of overhead crane

3) Application scopes

1) Portal crane;

2) Gantry crane used in mining and steel industries: suitable for crane with winch trolley; main and auxiliary hook crane; wire rope electric hoist; grab bucket gantry crane; explosion proof double beam bridge crane;

3) Remote control bridge crane

4) Material adopted

1) Heavy industry: cast iron

2) Chemical industry: stainless steel

4) Installation procedure

1) Find the mechanical position where motion needs to be detected or restricted;

2) Choose the appropriate installation method based on the type of crane limit switch and specific situation;

3) Secure the body of the limit switch firmly onto the mechanical equipment;

4) Design the motion path of moving parts as contacts that can trigger limit switch;

5) Connect the contacts of the limit switch to the input of the control system (such as PLC).

6) After power on, test the operation of the limit switch to ensure that it can be triggered normally when it reaches the preset position during operation. 

5) Technical parameter

Ratio	Base Fixing	Flanged Fixing	No.of Microswitch 2 - 3 - 4	Potentiometer 2.5 /5 / 10 kΩ	Rear Shaft	Microswitch Cams
012	FGR100124	FGR100124F	4 silver plated	NO	NO	STANDARD
033	FGR100334	FGR100334F		NO	NO
050	FGR100504	FGR100504F		NO	NO
075	FGR100754	FGR100754F		NO	NO
100	FGR101004	FGR101004F		NO	NO
150	FGR101504	FGR101504F		NO	NO
200	FGR102004	FGR102004F		NO	NO
400	FGR104004	FGR104004F		NO	NO

6) FAQ

1) How does the limit switch work in a bridge crane?

Answer: the limit switch detects when the hook or the trolley reaches the end of its travel path, and automatically shuts off the power supply of the crane motor.

2) Can additional limit switches be added to the existing EOT crane?

Answer: Yes, if safety or regulatory compliance needs to be improved, additional crane limit switches can be added to existing overhead crane.

3) How to extend the service life of cranes with limit switch?

Answer: the limit switch can prevent overhead crane from hitting the moving parts on the end of bridge too violently, thereby minimizing the impact on crane gears and brakes.

Similarly, limit switches can prevent the crane's trolley from traveling too far along crane bridge, thereby reducing the wear of crane's wheels and rails and gradually reducing pressure on crane components.

CTECH’s photosensor installed at two 12.5t overhead crane in precast industry to avoid collision of both cranes. Both cranes distance were set 3m apart for safety reason.