Type CRT30 measures the time gap between two signals read by a sensor on a revolving or cycling mechanism. When the time gap becomes greater then the pre-set value, the device itself activates and signals a drop in velocity or full stop of the mechanism’s movement. Lower values compared to pre-set value do not activate the device. Type CRT30 rotation control sensor is available with a control unit independent from signal reading sensor (CRTP) or with the sensor incorporated in the device (CRT30).
Type CRT30 rotation control sensor is ideal for control of slipping transport belts, chain breakage, power interruption or overloads etc in applications such as belt transport, chain elevators, mills, grinders, pumps, kneading mixers and in other situations where movement control of revolving or cycling mechanisms is necessary.
Application / function: Type CRTP: Type CRT30 rotation control sensor is composed of a central electronic unit inside a plastic undecal insertable housing and a detecting sensor that works according to inuctive, capacitive or photoelectric principles in NAMUR-NPN-PNP versions. Utilisation of sensors with various size and shapes permits CRTP to be useful in any detecting of different space and distances which makes its utilisation vast.
Programmable functions: Type CRTP: Time and RPM The time range is from 0.03 sec. and 512 sec. distributed on nine scales which can be selected by means of the front mounted dip switches. The selected scale can then be adjusted by means of a potentiometer which has a graduated scale from 0.05÷1. It is possible by summing two or more scales to obtain full scale values which are different to the standard ones, this is obtained by placing the switch with the values preselected in the ON position (e.g.: Pos. 2 and 4 swith on corresponds to a full scale of 144 seconds). This operation can also be carried out on the RPM scale.
Function A-B When the CRTP gives out a signal of standstill or slowing down it is possible to have two types of functions which can be selected by switch number 10 on/off.
A: in order to reactivate the unit it is necessary to switch the power supply off and then on or reset.
B: the unit can be reactivated by means of the first impulse which arrives from the sensor or by means of the reset. This is obtained with the switch in the OFF position. Sensor - NAMUR - NPN - PNP It is possible to select via the switch number 11 in the ON/OFF position the type of logic for the sensing unit. In the ON position it is possible to connect NPN sensors and in the OFF position PNP and NAMUR sensors. Rotation control - shaft stand still These functions can be selected by switch number 12 and in this way both functions can be carried out by the same instrument. Rotation control - switch off With power applied the relay switches and maintains this position as long as the impulses from sensors are within the set time. If within that time no impulse is received the relay changes state giving an alarm condition, in the case of lack of power supply the relay changes state (see working diagram) giving the alarm condition (slowdown or stopping). Shaft stand still control - switch on In this situation the relay works in exactly the opposite way. The relay activates when no impulse arrives within the set time thus showing the shaft standstill condition. In the case of loss of power supply the relay changes state thus giving the alarm condition (shaft movement).
Type CRT30 is a rotation control device with the shape of a cylindrical threaded metallic sensor M30x1.5 inductive sensing featuring an activating distance between 4 and 6 mm on metallic material. Type CRT30 rotation control sensor may be limited in the amount of applications where we can use it because of its 30 mm diameter but in other cases it proves to be interesting because we have both detecting and control all in the same device. Moreover the power supply tension range from 18-50 D.C. and 18-240 A.C., various programmable functions and output exchange relay make of this device a compact and practical instrument for installers.
Programmable types CRT30 available: CRT30-R10L = 6÷150 RPM detectable by means of trimmer. Functions A and B available by means of selector. CRT30-R10V = 120÷3000 RPM detectable by means of trimmer. Functions A and B available by means of selector. CRT30-R10L/V = two range of RPM can be detected (6÷150 RPM and 120÷3000RPM) and selected by means of trimmer regulator. Function B pre-programmed and fixed. Function types A-B: when CRT30 detects full stop or velocity decrease you can have two working functions (excluding type CRT-R10 L/V): * A: to re-activate the device you must switch off power and then turn on again. * B: the device re-activates itself automatically as soon as the number of rotations exceeds alarm range. Type CRT30 rotation control sensor is available from Veederline.