Timers are used to produce a delay in an application. There are different types of timers like ON Delay timer, OFF Delay timer Which are utilized for different applications.
In ON Delay timer, Output get ON after some time. While In OFF Delay timer, Output get OFF after some time. Selection of timer; Is all depend upon the application. Both ON & OFF delay timers are explained through a GIF below.
- In a GIF of ON delay timer, It is clearly seen that at initial stage switch remains at off position. When switch is shifted to ON position, the output remains off for a set time. Then it turns on until the switch is shifted to the OFF position.
- In OFF delay timer below, Initially switch remains at off position. When switch get ON, Output get ON parallely & remains ON for some set time period. At last, It get OFF.
This post is about Cyclic Timer. Cyclic time which we can say a hybrid timer; Is a Combination of both ON & OFF delay timer. For better explanation, We are elaborating, Cyclic Timer XC800 by Selec.
CYCLIC TIMER XC800 by Selec
This timer operates in an alternate manner such that ON,OFF,ON,OFF,ON,OFF. Both the ON&OFF timing can be adjusted. In along, Which Timer is going to operate first; ON delay or OFF delay; is all selectable.
FEATURES
- Finger safe Terminals.
- Universal power supply AC & DC ranges from 20 to 240 Volts.
- 6 Time ranges 0-1 sec,0-1 Minute, 0-1 Hour, 1-10 secs., 1-10 Minutes, 1-10 Hours.
- 2 Changeover Relays (SPDT)
- LED indications for power & relay ON.
- Uneven ON & OFF times. Both the ON & OFF timer’s ranges are individually selectable.
- There is selection which timer is going to operate first.
SELECTION OF RANGE & UNITS
In this timer, DIP switches shown in an image above, Allow multiple functions. These include selection of time units and its multiplier. They also determine Which timer operate first, ON Timer or OFF Timer.
- Dip switches 1,2,6,7 are used to select the time units like second, minute or hour. for both the SPDT.
- 3&8 switches are used to select the multiplier 1 or 10.
- Dip switches 4&5 are used to select ON delay first or OFF delay first.
For example, In an image of DIP switches above,
- switches 1, 2, & 6, 7 are present in up position. This position represents the timer’s unit in seconds.
- 3 & 8 switches are placed in downward position which represents the multiplier unit 1.
- The 4th switch is present in up position. The 5th switch is in down position. This configuration of 4th & 5th switches means the ON timer will operate first, followed by the OFF timer.
- In a very first image, t1 knob is set at 10 that means the time unit is 10 sec.
- Knob for timer t2 is set at 1.5 that means the time units for timer t2 is 1.5 seconds.
- When timer get energized, Relay will operate first for 10 sec. & then relay get off for 1.5 sec. After that relay get ON again &Cycle remains continue.
TERMINAL CONNECTIONS
These timers are controlled by micro-controller which operates at DC minor voltage level. Power circuit can not be controlled directly that’s why this timer is equipped with changeover relay.
CHANGEOVER RELAY (SPDT)
A changeover relay (PDT- single pole double through) is used to operate power circuit through a control power supply.
We can say micro-controller is controlling the power circuit indirectly through changeover relay.
Changeover relay has three contacts : Common, NO & NC contacts.
- At normal state, Common contact is connected with the NC contact.
- When the electromagnet get energized, Common contact connects to NO contact.
- When electromagnet get de-energized common contact shifted back to NC contact.
This timer has two Changeover Relays . Each Changeover relay has 3 terminals which means total 6 terminals for relay connections. While, It has two terminals for power supply connections.
Relay 1 has terminals 15,16&18 . In which 15 terminal is common while 18 is NO while 16 is NC. Relay 2 has terminals 25,26 &28 In which 25 terminal is common terminal,26 is NC while 28 is NO. A1 & A2 terminals are power supply terminals.
TIMING DIAGRAM OF OPERATION
In this Timer, Knob t1 represents OFF timer while knob t2 represents ON timer. DIP switch 4 & 5 are used to select which timer will operate first, ON timer or OFF timer.
When DIP 4 is set above and DIP 5 is set below, The ON timer operates first. It operates according to the knob t2. Then, the OFF timer will operate according to the knob t1.
When DIP 4 is set down and DIP 5 is set above. The OFF timer operates first according to the knob t1. Then, the ON timer will operate according to the knob t2.
APPLICATIONS OF 800XC TIMER
Production line conveyor
To better understand Timer 800XC, we will discuss the production line conveyor. This conveyor runs through the Timer 800XC by SELEC.
In this scenario, The products are moving on conveyor & get stopped at fixed intervals. An accessory needed to be fitted on each product one by one. Conveyor stops for fixed interval until the accessory is get fitted. Then it moves On, until the next product in line reaches the station for accessory fitting.
Conveyor in this system is running in alternate manner. It runs for some seconds & then it get stops for some seconds. And cycle remains continue.
In Electrical Connections, We are assuming that conveyor’s motor is Induction motor which is mounting with some gear mechanism. Motor is running on DOL starter. Timer XC800 is controlling the contactor in a cyclic manner.
In Electrical Power wiring above, Power supply & Motor terminals are connected across the contactor.
In Control wiring, Control phase first passes through the MCB. Then it passes through NC contacts of the thermal overload relay. After that, It passes through the NO contact of the timer. At last, control phase is connected to contactor While neutral is directly connected to contactor.
SUMMARY
- Timers are used to produce a delay in an application. There are different types of timers like ON Delay timer, OFF Delay timer Which are utilized for different applications.
- In ON Delay timer, Output get ON after some time. While In OFF Delay timer, Output get OFF after some time.
- Cyclic time which we can say a hybrid timer; Is a Combination of both ON & OFF delay timer. XC800 by SELEC is a type of cyclic timer.
- This timer XC800, operates in an alternate manner such that ON,OFF,ON,OFF,ON,OFF. Both the ON&OFF timing can be adjusted. In along, Which Timer is going to operate first; ON delay or OFF delay; is all selectable.
- For selection of time units & timer selection, DIP switches are provided.
- This Timer is controlled by micro-controller which operates at DC minor voltage level. Power circuit can not be controlled directly that’s why this timer is equipped with changeover relay.
- A changeover relay is used to operate power circuit While DC supply of timer controls the changeover relay. We can say micro-controller is controlling the power circuit indirectly through changeover relay. Changeover relay has three contacts Common, NO & NC contacts.
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