Technical data
Enclosure design	Distribution board
Output contacts	2 C/O contacts
Time function(s)	On-delay
Width	17,5 mm
Type	IK 7825
Variant
Contact equipping	1 changeover contact delayed
Nominal voltage	AC 230 V
Time range	0,05 - 1 s

The Dold time relay type IK7825.81AC50HZ230V0,05-1S is a delayed-on time relay for industrial control applications. It is used for time-controlled activation of switching operations, where the contact only switches after a set delay time. The device is designed for use in installation distributors and has a width of 17.5 mm, making it suitable for standard control panels. The rated voltage is AC 230 V, and the time delay can be adjusted in the range of 0.05 to 1 second. The time function is delayed-on, meaning the contact only switches after the set time has elapsed once the input voltage is applied.

Applications
This time relay is used in industrial plants where time-controlled switching operations are required, for example, to delay motor start-up, control lighting systems, or synchronize process steps. It is designed for continuous operation and can be used in environments with an operating temperature of -20 °C to +45 °C. Storage is possible at -25 °C to +70 °C. The relative humidity is up to 95 % at 40 °C. The operating altitude is limited to a maximum of 2000 m above sea level.

Functions and Equipment in Detail
The device features a button for manual actuation of the contact, which also serves as a switching position indicator. This allows for visual inspection of the switching state. The contact configuration includes a changeover contact that switches with delay. The maximum thermal current rating is 16 A. The repeatability is ≤ 0.5 % + 10 ms, ensuring high precision in repeated switching operations. The time delay is continuously adjustable and is set on a relative scale with a ratio of 1:20.

Technology Explained Simply
The relay operates according to standard EN 61812-1, which applies to time relays in industrial applications. The input voltage is supplied via terminals A1/A2. The output contacts (15, 16, 18) are configured as changeover contacts. The contact materials consist of AgSnO₂, ensuring high service life and reliability during switching operations. The electrical life is up to 150 x 10⁴ switching operations at ohmic load and AC 230 V with 6 A. The mechanical life exceeds 3 x 10⁶ switching operations. The contact release time is less than 30 ms. The reset time is approximately 60 ms after the delay time has elapsed and approximately 700 ms during the delay time.

Compatibility and Accessories
The relay is designed for a rated frequency of 50 Hz, with a frequency range of ±5 %. The voltage range coverage is 90 to 110 % of the rated voltage. The release voltage is 15 % of the rated voltage. The rated power is 2.3 VA for alternating voltage. The maximum permissible fuse is 16 A gG/gL according to IEC/EN 60947-5-1. The switching frequency is up to 1000 switching operations per hour. The housing is designed for installation distributors, with an IP 40 protection rating for the housing and IP 20 for the terminals. The housing is made of thermoplastic with V0 behaviour according to UL 94.

Mounting and Installation
Mounting is carried out in standard installation distributors. The terminals comply with standard EN 50005 and are designed for connections according to DIN 46228-1/-2/-3. The vibration resistance is an amplitude of 0.35 mm at a frequency of 10 to 55 Hz. The climatic resistance corresponds to standard 20/045/04 according to IEC/EN 60068-1. The insulation test voltage is 2.5 kV for 1 minute. The overvoltage category is III, and the protection level is 4 kV at pollution degree class 2 (basic insulation) according to IEC 60664-1.

Advantages in Operation
The relay offers high switching accuracy and reliability in repeated switching operations. The continuously adjustable delay time allows flexible adaptation to different requirements. The integrated switching position indicator facilitates maintenance and diagnostics. The compact design with a width of 17.5 mm enables efficient space utilization in control panels. Compliance with standard EN 61812-1 ensures safety and reliability in industrial use. EMC tests according to IEC/EN 61000-4-2 to -4-6 and emission limits according to EN 55011 (Class B) ensure functionality in electromagnetically demanding environments.