SELEC Cyclic timer 800XC with full Description |

 SELEC TIMER 800XC

This timer operates as continuous alternate cycle with selectable on & off time. Timer’s relay get on & off according to the set time. Both on & off functions have independent time setting which is briefly explained below:

 

• WHEN RELAY OFF FIRST (T1 execute first then T2 & then again T1 & T2)

• WHEN RELAY ON FIRST (T2 execute first then T1 & then again T2)

SPDT Relay

• This time contains 2 SPDT relays. SPDT stands for “Single pole double through“.
• SPDT relay contains 3 contacts  NO, NC & common.
• At starting, When relay is off; common contact is connected with NC contact.
• When relay get on ; common contact get connected with NO contact.
• Through these contacts circuits are implemented.
• Both the SPDT works simultaneously parallelly.

FEATURES OF SELEC 800X

• Cyclic timer with unequal on & off time
• 6 Time ranges
• Universal supply voltage
• LED indications: power on, relay on
• Finger safe terminals
• 2 Changeover relays

•   20 to 240V AC (50/60Hz)
•   12 to 240V DC

•   0-1Sec/min/hour (ON Time)
•   0-10Sec/min/hour (ON Time)
•   0-1Sec/min/hour (OFF Time)
•   0-10Sec/min/hour (OFF Time)

1.   Power ON
2.   Relay ON

•   Operating: 0 to 50°C
•   Storage: -20 to 75°C

1. Relay 1[15(common),16(NC) & 18(NO)]
2. Relay 2[25(common),26(NC) & 28(NO)]

SWITH SETTING OF SELEC 800x

• Switches 1,2 & 6,7 are provided for time unit selection. 1,2 switches for OFF time & 6,7 switches for ON time.

• Switches 3&8 set multiplier for OFF & ON time respectively. When switch in on position than multiplier is 1 otherwise multiplier is 10.
• Switches 4&5 are provided to select the mode which timer T1 or T2 will execute first. When 4 is off & 5 is on than ON time will execute first. When 5 is on & 4 is off than OFF time will execute first.

APPLICATIONS

Circuit for non continuous conveyor system with SELEC 800X

We can use the timer SELEC 800X at a system where conveyor is taking rest in fixed running intervals. We can say, conveyor has both on & off Time which is selectable. Let suppose conveyor motor is 1.5KW, 3phase 415Volts-50Hz.

In power wiring, 3phase supply directly connected on the contactor through 10Amps 3pole MCB & motor terminals are connected to the contactor through thermal overload relay with ampere range 2.5to 4Amps. Control wiring is explained below:

In this circuit, we have arranged both the running modes ‘auto & manual’. Mode is selectable through selector switch. In manual mode, Conveyor will run continuously. In auto mode, conveyor will run in ON&OFF intervals through the cyclic timer in which we can set ON&OFF time of conveyor. It doesn’t matter Whether we are running the conveyor in auto or manual mode, we have to start & stop the conveyor through push buttons.

Since all the components have supply voltage is 230V AC that’s why neutral is directly connected to 8 pin relay, Timer & contactor. First, Phase is passing through the NC (Emergency switch) which is used as a safety, Than this phase is passing through the NC (stop) & NO (start) of push button in a series manner. At last, phase is connected to relay coil.

When we press NO(Start) push button, relay’s coil get energized which results relay’s contacts get changed. After that when we release start push button, relay get hold because relay’s NO contacts are connected in parallel across NO (Start).

Another NO of relay is connected to 2way selector switch. Since another NO of relay is connected to phase, after relay get hold phase become available to main contact of selector switch. One point of selector is connected to energize the timer & another point of selector is directly connected with motor’s contactor through NC contact of thermal overload relay. Contactor through NC of thermal overload relay is also connected with timer’s NO.

❓ Frequently Asked Questions (FAQs)

1. What is the SELEC 800XC Cyclic Timer?
The SELEC 800XC is a cyclic timer device used in control systems to automatically switch its output on and off in continuous cycles, with independently adjustable on and off durations.

2. How does the cyclic timer work?
It alternates the relay between ON and OFF states based on the set timings: one knob sets the ON duration and another sets the OFF duration. You can also choose whether the cycle starts with ON or OFF.

3. What applications is this timer used for?
This timer is commonly used in automation and industrial control—for example, controlling conveyor systems that need to run periodically with fixed rest intervals.

4. What voltage range does the 800XC support?
It supports a wide supply voltage range from 20 V to 240 V AC and 12 V to 240 V DC, making it suitable for various power systems.

5. What are the key features of this timer?
Key features include:

• Cyclic ON/OFF timing with uneven durations

• Universal supply voltage

• LED indicators for Power ON and Relay ON

• Finger-safe terminals and 6 selectable time ranges.

6. How many relay outputs does the timer have?
The 800XC includes two changeover (SPDT) relay contacts, allowing flexible control of external loads.

7. Can I adjust the time ranges?
Yes — the timer offers multiple time ranges from fractions of a second up to hours for both ON and OFF durations, allowing fine-tuned control.

8. How accurate is the timing?
The timing accuracy is typically within ±5% of full scale, with repeatability around ±0.5% or 50 ms.

9. How is the timer mounted?
It is designed for DIN rail mounting, making it easy to integrate into industrial control panels.

10. What protections or indications does the timer have?
It has LED indicators to show when the power is on and when the relay is active, ensuring easy status monitoring.