Selec 600XU and Selec 600DT: Multifunction timer relays from Selec in the spotlight

The Selec 600XU and Selec 600DT offer numerous time functions. However, their full potential still often remains untapped. This needs to change immediately, and we can help you with this! Here you can find out what advantages the Selec timer relays offer and what time functions they can perform for you.

The Selec 600XU and Selec 600DT conceal untapped potential

What advantages do the two Selec timer relays offer?

Time functions of the Selec 600XU and Selec 600DT timer relays

FAQs regarding the Selec 600XU and Selec 600DT

The Selec 600XU and Selec 600DT compared: which timer relay is the right one for you?

Selec 600XU and Selec 600DT timer relay key visual

Do you already know which timer relay you require?

Go directly to the timer relays

Would you like a personal consultation?

Go to the free consultation

Do you require a brief overview of the Selec time functions?

Download brief overview

The Selec 600XU and Selec 600DT conceal untapped potential

The Selec 600XU and Selec 600DT are versatile timer relays, or to be more precise, multifunction timer relays that combine a wide range of time functions. However, the mere presence of these functions is not enough if you are not familiar with their possible applications.

Here we would like to clear up the ambiguities surrounding the two Selec timer relay models, and provide some examples for possible areas of use, so that you can recognise their full potential and make use of them for your projects.

What advantages do the two Selec timer relays offer?

The two multifunction timer relays from Selec, the 600XU and the 600DT, impress with the following advantages for your applications:

Versatility: Suitable for various applications − from time monitoring to cycle control
Precise time monitoring: Effective process control and planning
Simple connection: Fast mounting on 35 mm DIN rails including simple wiring via screw terminals
Reliable quality: Fulfil high quality standards in accordance with ISO 9001
Cost-effective: Enable the implementation of the most varied of time functions, without the need for a more costly and complex control unit

Time functions of the Selec 600XU and Selec 600DT timer relays

The Selec 600XU and Selec 600DT timer relays offer a host of time functions, with a view to realising precise time-controlled processes.

Here you have a comprehensive overview of the individual functions — from the conditions, to the breakdown of the designations, as well as explanations and practical application cases. This will allow you to develop a more in-depth understanding of the diverse usage possibilities of these relay models.

Selec timer relays: designations & functions − breakdown

The designations that are assigned by Selec are abbreviated to letters. Some of these letters are assigned to different functions for the 600XU timer relay as for the 600DT, and vice versa. There are also letters that are used for identical functions. The following overview should make it simpler for you to make use of the time functions.

Time functions	Selec 600DT	Selec 600XU
ON delay	A	A
Interval	B	B
Asymmetrical cyclic OFF first	C	-
Asymmetrical cyclic ON first	D	-
Cyclic equal OFF first	E	C
Cyclic equal ON first	F	Ci
Pulse output	H	D
Delay on break	J	E
Delay on make / break	K	F
Interval after break (negative edge ***)	L	H
Single shot	P	I
Retriggerable single shot	Q	J
Latching relay	R	K
Delay with totalise (negative edge )*	T	Ai
Interval with totalise (negative edge )*	U	Bi

Conditions for the execution of the time functions

In order that time functions can be executed, certain conditions must be fulfilled.

The following therefore applies: If no control contact Y1 is required for the time function, the process is started upon application of the supply voltage (U) or (VS).

The functions without a control contact would be, in the case of Timer Relay 600XU, A, B, C, Ci and D, and for the 600DT the functions A, B, C, D, E, F and H.

If, however, a control contact Y1 is required, then the supply voltage (U in the case of the 600XU or VS in the case of the 600DT) must be continuously connected and the timer relay is activated via the control contact. In the case of the 600XU timer relay, this concerns the functions E, F, H, I, J, K, Ai and Bi and with the 600DT it concerns the functions J, K, L, P, Q, R, T and U.

Time function overview for the Selec 600Xu and the Selec 600DT: explanation and application examples

The following table offers a detailed overview of the time functions of the Selec 600Xu and Selec 600DT timer relays, including explanations of the functions and application examples.

Time function(s):	Explanation:	Application example/area of use:
ON delay (A) for the 600XU and the 600DT	The switching function is only executed after the delay time has lapsed.	Irrigation system control in agriculture (Example I): The timer relay is activated by flipping the switch. Once the configured response time delay has lapsed, the irrigation system in the greenhouse starts up.
Interval (B) for the 600XU and the 600DT	The switching function is executed immediately and only ends after the configured time.	Irrigation system control in agriculture (Example II): The timer relay is activated by flipping the switch. The irrigation system in a greenhouse starts immediately. Only once the programmed interval timing relay delay has lapsed is the timer relay switched off.
Asymmetrical cyclic only with the 600DT ... OFF first (C) ... ON first (D)	Cycle control is performed with time intervals of differing lengths ((t1) and (t2)), beginning with a switch-off time (t1). Cycle control incorporates time intervals of varying lengths ((t1) and (t2)) and begins with a switch-on time (t2).	Sauce production within the food industry: A liquid must be stirred for 10 minutes every hour in order to produce a homogeneous mixture. You can select whether to begin with the pause of one hour (1) or whether the stirring should start immediately (2).
Cyclic equal ... OFF first (E or C) E in the case of the 600DT / C in the case of the 600XU ... ON first (F or Ci) F in the case of the 600DT / Ci in the case of the 600XU	The cycle control is characterised by its flashing sequences, which begin with a switch-off time and then alternate with switch-on times of consistent length. Cycle control starts with a switch-on time for the flashing sequences and then alternates with switch-off times of consistent length.	Lighting systems in industrial facilities: An LED is switched on after a pre-configured time delay (t), which is followed by a switch-on time of (t), before the cycle starts over from the beginning. Because the switch-off time is identical to the switch-on time, this produces a symmetrical flashing pattern. The same as for example 1, except the start takes place with a pre-defined switch-on time.
Pulse output (H or D) H in the case of the 600DT / D in the case of the 600XU	The timer relay waits for a predefined time (t1) before it sends a pulse. The duration of the pulse (t2) is also defined.	Control of fault-prone industrial facilities: With the time-delayed start-up of machines after a power failure, to avoid damage and guarantee smooth operation.
Delay on break (J or E) J in the case of the 600DT / E in the case of the 600XU	As soon as control signal Y1 is issued, the switching function starts. After the switching off of Y1, the pre-defined time (t) starts to count down. As soon as the time has lapsed, the time function switches off. If, after the switching off of Y1 within a time (ta) < (t), Y1 is switched on again, the time function starts over again.	Ventilation management in the building industry: Once a certain trigger event has been reached, such as the reaching of a certain room temperature, ventilation continues to run for a pre-defined time before returning to its idle state. This guarantees efficient air purification without reacting to temporary fluctuations and simultaneously minimizes unnecessary switching cycles of the exhaust air system.
Delay on make / break (K or F) K in the case of the 600DT / F in the case of the 600XU	With the control signal Y1, the trip time delay starts and, once it has lapsed, the recovery time delay starts immediately. The set time (t) is valid for both the trip time and for the recovery time delay.	Maintenance management in the production industry: After a fault (response time), normal production should not resume immediately. The response time serves as a buffer in order to correct potential short-term faults before the system switches back to normal operation. This can prevent damage to machinery caused by the premature resumption of production.
Interval after break (negative edge **) (L or H) L in the case of the 600DT / H in the case of the 600XU*	The timer relay triggers when the control signal Y1 stops and the configured time (t) starts to count down. If, after the switching off of Y1 within a time (t1) < (t), Y1 is switched on again, the time function starts over again.	Time-controlled industrial alarm management: In an industrial monitoring system, an alarm is triggered after a certain signal (negative edge) has been detected. However, this does not happen immediately, but rather only once a predefined time period has lapsed. This prevents an unnecessary alarm from being triggered in case of short-term fluctuations. Only persistent faults result in an alarm activation.
Single shot (P or I) P in the case of the 600DT / I in the case of the 600XU	With this time function, a control signal Y1 can be extended by the configured time (t).	Time-controlled pump control units in wastewater systems: The pump generally stops immediately if a tank is full. In case of a temporarily elevated liquid requirement, it can occur that it is not required to stop immediately after achieving the maximum fill level. The function prevents redundant switching on and off processes and extends the life of the pumps.
Retriggerable single shot (Q or J) Q in the case of the 600DT / J in the case of the 600XU	The time relay is reset by each new control signal Y1 and the pre-programmed delay time (t) starts again from the beginning. The pulse time (ta) must not be longer than the set time (t).	Gate control in logistics: After pressing the pushbutton, the gate opens and the pre-defined time starts to lapse. If the pushbutton is pressed again or if a passing object is detected by a light barrier, the elapsing time is extended and the function starts over.
Latching relay (R or K) R in the case of the 600DT / K in the case of the 600XU	This function enables the timer relays to be switched on/off via Y1 with each control pulse.	Industrial lighting control: A permanent switch on/off process can be realised with a button. This allows the light in a room to be controlled with several buttons, for example, without having to set up an elaborate cross-connection.
Cummulative delay (negative edge )* Delay (on break) with totalise (T or Ai) T in the case of the 600DT / Ai in the case of the 600XU Interval with totalise (U or Bi) U in the case of the 600DT / Bi in the case of the 600XU	The time of the negative edge of the control signal ((t1), (t2)…) is added up until it corresponds to the configured delay time (t) and the relay switches on. The time of the negative edge of the control signal ((t1) and (t2)...) is added up until it corresponds to the configured delay time (t) and the relay switches off.	Bulk material processing in pneumatic conveyor systems: To ensure that conveyance only takes place with sufficient pressure in the system, a pressure monitoring system with a timer relay and cumulative trip time delay can be used. The cumulative trip time delay ensures that the pressure in the system is stable before the conveyor system is activated. This prevents unwanted activations due to short-term pressure fluctuations. Refrigeration system control in a food storage facility: The refrigerator system normally switches off once the storage temperature has reached the desired value. The time function ensures that the system does not switch off immediately if the temperature briefly falls below the threshold value (e.g. as a result of the temporary opening of a warehouse door). This prevents the unnecessary switching on/off of the system and extends the life of the system while also optimising energy consumption.
*** Negative edge = voltage change from high to low

Download the Selec time function overview free of charge

FAQs on the Selec 600XU and Selec 600DT – the most commonly asked questions from Automation24 customers

What is the difference between supply voltage (U) and control contact Y1?: There are time functions that use the control contact Y1. With these functions the supply voltage (U) must be permanently connected and individual time functions are activated or controlled via the control contact. In the case of time functions without control contact Y1, the function starts when the supply voltage is applied (U)

What differentiates Contact 25 from Y1?: There is no difference whatsoever. It's just that the contact on the device itself is designated as Contact25, while on the datasheets it is called Y1.

How do you read the adjustment potentiometer?: The central dial from 1 to 10 corresponds to an adjustment value range from 0 to 100% of the time configured above.

How do I access the basic function menu?: For the digital timer relay, press and hold the M.

Why does the timer relay not respond to switched time functions?: The timer settings or programming of the timer relay Selec 600XU must be configured with the unit switched off. The voltage must be switched off and on again in order for your settings to be applied. With the Selec 600DT, the adjustments are saved immediately.

Can timer relays be connected in series?: Yes, timer relays can be connected in series in order to execute various time-controlled actions one after the other. In this way, so-called multi-time functions can be realised. Here is an example: you want to carry out two tasks. First of all, a gate should remain open for two minutes after opening, and secondly, a warning light should flash at second intervals during this time. By chaining together two timer relays, you can coordinate these actions. A timer relay controls the opening of the gate for precisely two minutes (function 1), while the other timer relay simultaneously flashes the warning light at one-second intervals (function 2). This approach enables the implementation of complex time-controlled functions.

In which cases should you favour timer relays over a control system?: If you only require a limited number of time functions, then timer relays are the best choice (both functionally and in terms of price).

Where are the Selec 600XU and Selec 600DT timer relays produced?: The timer relays are produced in India and meet the high quality standards of Selec products, as evidenced by their ISO 9001 certification.

Are the multifunctional timer relays easy to install?: Both timer relays can be quickly assembled. They can be easily mounted onto standard 35 mm DIN rails and wired with screw terminals.

Who can I contact if I have further questions regarding the Selec timer relays?: Should you have any outstanding questions, our competent experts from the Automation24 technical support team would be happy to answer them for you. Feel free to contact us.

The Selec 600XU and Selec 600DT compared: which timer relay is the right one for you?

Selec timer relay type	600DT-CU	600XU-CU
Technology	Digital	Analogue
Application	Suitable for more complex applications over a longer period of time.	Intended for simpler applications, over a shorter period of time.
Operation	The time can be conveniently adjusted via the display. The unit can be altered.	Time can be set via a traditional poteniometer. The unit always remains the same.
Adjustable time intervals	(t1) and (t2) are adjustable.	Only one time interval can be selected.
Number of time functions	15 pieces	13 pieces
Accuracy	Adjustment: ±0.1% of the configured time or ±5ms (higher value).	Adjustment of the end value.
	Order the Selec 600DT-CU	Order the Selec 600XU-CU

The Selec 600XU and Selec 600DT multifunction timer relays offer a reliable and cost-effective solution for time control tasks in various applications. Discover their full potential and use them for your projects.

Back to the overview