M. M. Sankhla Electricals

Reliability and safety are pre-requisites in the choice of the control contactor. Siemens 3TH30 contactor relays satisfy these criteria and thus offer the right choice to the customer.

Applications:

• 3TH30 are used in control circuits for switching and signaling purpose. Also they are used for interfacing with the electronic circuits.

Benefits and features:

• Choice of auxiliary contacts: 3TH30 contactor relays comes with 4 contacts as a basic unit (4NO, 3NO+1NC, 2NO+2NC). However the contacts can be extended upto 8 contacts by adding maximum 4 auxiliary contact blocks to this basic unit. This offers flexibly in selection and configuration.
• Choice of mounting: 3TH30 can be mounted on 35mm DIN rail and they are also suitable for screw mounting.
• Long Life
• Superior design of current carrying parts, contact system and the magnet system increases the reliability which also results into higher electrical and mechanical endurance.
• High reliability Double Break Parallel Bridge contact mechanism This mechanism is available with 3TH30. Such contact mechanism ensures reliable contact at low voltage and low currents (5mA at 17V DC). It also offers unmatched reliability as well as capability to integrate directly into PLC or instrumentation circuits.

User friendliness and safety:

• Positively driven contacts: 3TH30 auxiliary contactors satisfy the conditions for positively driven operation between NO and NC contacts. NO and NC contact do not close at the same time. This is extremely important when they are used in safety circuits of critical applications. This ensures operator safety even during abnormal condition.
• SIGUT Termination
• Figure touch proof terminals: It protects against accidental contact with live parts which ensures operator safety.
• Funnel shaped cable entries: Reduce wiring time by facilitating quick location of the connecting wire.
• Cable end-stop: It decides the insertion depth of the connecting wires. Since the insertion depth is predetermined, insulation of the cable can be cut accordingly and the possibility of insulation getting inadvertently caught under the terminal is avoided.
• Captive Screws: This feature prevents the screws from falling down thereby facilitates the wiring. Hence, the auxiliary contactors are delivered with untightened terminals. This eliminates the operation of untightening terminals before wiring.
• Lug less termination: This feature helps in reducing the termination time.

Introduction:
The technical and descriptive information on the function, construction and selection of the new types of 3SE3 limit switches is presented here.
These limit switches are actuated by straight edges, cams, stops or plates etc. and give control commands for the further progress of the switching program or of the manufacturing/processingsquence. For the various control applications there are 2 ranges available, namely open type and metal enclosed limit switches with 3 different versions of contact configuration.
There is a wide range of actuators suitable for different operations/ actuation conditions, enabling the user to select the most optimum one for the particular application. Specially designed compact housings also allow for optimum installation and convenient cable entry. The design, materials used and manufacturing processes ensure that 3SE3 limit switches guarantee the reliable functioning of control and auxiliary systems.

Standards:

• The 3SE3 limit switches conform to the following standards:
• Electro-mechanical control switches. IS: 13947-5-13 and IEC: 947-5-1-3
• Stipulation of mounting dimensions, operating points,housing form and actuator form. DIN EN 50047 and DIN EN 50041

Applications:

• Limit switches are used in automatic control circuits where mechanical positions have to be converted into electrical signals for controlling remote starters, contactors etc. The 3SE3 limit switches are ideally suited for control of machine tools, elevators, cranes, conveyors, gates, doors and various other applications.
• Copyright © 2020 M M Sankhla Electricals. All rights reserved

SICONT Limit Switches Type 3SE3 upto 500 VAC, 600 VDC, 10A

The 3UA / 3UC thermal overload relays are suitable for customers from all industries, who want guaranteed optimum inverse time delayed protection of their electrical loads. The relays meet the requirements of IS/IEC 60947-4-1.

Application:

• 3UA overload relay: 3UA5/6 are 3 pole adjustable bi-metal overload relays mainly suitable for normal starting applications. They provide accurate and reliable protection to motors against overload as per CLASS 10A. They also offer protection against single phasing and unbalanced voltages.
• 3UC overload relay: 3UC5/6 are 3 pole adjustable, saturable CT operated bi-metal overload relays mainly suitable for heavy starting applications (i.e. when heavy masses are to be put in motion resulting in larger starting period). They provide accurate and reliable protection to motors against overload as per CLASS 30. They also offer protection against single phasing and unbalanced voltages.
• If single-phase AC or DC loads are to be protected by the 3UA / 3UC thermal overload relays, all three bimetal strips must be heated. For this purpose, all main current paths of the relay must be connected in series.

Relay Overview:
Overload relay operates on the bi-metallic principle. The heater winding wound on the bimetal strips carry the current flowing through the motor. In case of overload, the current carriedthrough the heater winding is more than the rated current. This heats up the bimetals. Due to this bi-metal strips bend and open the NC contact of the relay, which is connected in the control circuit of the contactor, thus disconnects the motor from the supply. The tripping time is inversely proportional to the current flowing through the bi-metal strips. Bi-relays are therefore, referred to as “current dependent” and inverse-time delayed relays

• Connection for mounting onto contactors: Optimally adapted in electrical, mechanical and design terms to the contactors, these connecting pins can be used for direct mounting of the overload relays. Stand-alone installation is possible as an alternative (in some cases in conjunction with a stand-alone installation module).
• Selector switch for manual/automatic RESET (blue): With this switch you can choose between manual and automatic RESET. A device set to manual RESET can be reset locally by pressing the RESET button. A remote RESET is possible using the RESET modules (accessories), which are independent of size.
• TEST button (red): Trip circuit can be manually checked by using this button. During this simulation the NC contact (95-96) is opened and the NO contact (97-98) is closed. This tests whether the auxiliary circuit has been correctly connected to the overload relay. The relay must be reset with the RESET button if it has been set to manual RESET. If the thermal overload relay has been set to automatic RESET, then the overload relay is automatically reset when the TEST button is released.
• Motor current setting dial: Setting the device to the rated motor current is easy with the large rotary knob. (Recessed dial, hence no possibility of accidently change in current setting.)
• Trip indicator (Green): A separate mechanical Green Trip Indicator is provided on the front cover of the relay to indicate the tripped state of the ‘manual reset’ relay.

Siemens pioneered the AC23A concept with powerguard 3KL range, which has become an industry norm now. With Superswitch 3KL8, we take the industry standards to  a higher plane. 3KL8 range is superior not only to powerguard 3KL range but also to most other SDFs available in market today. The superiority is in terms of technical parameters such as operational and insulation voltage, life in terms of no. of switching cycles, no. of variants and ratings available. Hence this new range is called “Sentron Superswitch”.

Benefits:

• Versatile – suitable for all application
• Rugged – lasts long, low maintenance
• Low life cycle cost – higher return on investment
• User friendly – designed for indian conditions
• Safe – safety to plant and personnel

Application:

• 3KL8 Superswitches are suitable for diverse applications upto 690Vac, 50/60 Hz in motor feeders with Direct-on-line, Star-Delta, Soft starters and VVVF drive applications. They are suitable for wind mill generators, capacitor switching feeders, motor control centres and power control centres. 3KL8 switches are specially designed for high ambinent temperature applications and do no need any deration right upto 60°C.