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Power ON-delay Timer


Our Value Design Products Increase the Value of Your Control Panels. Single Mode Timers with power ON delay operation.

Time Ranges

Time range setting 0.1 s 1 s 10 s 1 min 10 min 1 h 10 h 100 h
Set time range 0.1 to 1.2 s 1 to 12 s 10 to 120 s 1 to 12 min 10 to 120 min 1 to 12 h 10 to 120 h 100 to 1,200 h
Scale numbers 12


Power supply voltage *1 24 to 240 VAC/DC, 50/60 Hz *2
Allowable voltage fluctuation
85% to 110% of rated voltage
Power reset Minimum power-OFF time: 0.1 s
Reset voltage 10% of rated voltage
H3DT-A2 At 240 VAC: 2.2 VA max., at 240 VDC: 0.7 W max.,
at 24 VDC: 0.3 W max.
H3DT-A1 At 240 VAC: 1.8 VA max., at 240 VDC: 0.6 W max.,
at 24 VDC: 0.3 W max.
Rated Insulation Voltage 250 VAC
Control output Contact output:
5 A at 250 VAC with resistive load (cosφ = 1),
5 A at 30 VDC with resistive load,
0.15 A max. at 125 VDC with resistive load,
0.1A max. at 125 VDC with L/R of 7 ms.
The minimum applicable load is 10 mA at 5 VDC (P reference value).
Contact materials: Ag-alloy
(Recommended fuse: BLN5 (Littelfuse) or 0216005MXEP)
Ambient operating
-20 to 60°C (with no icing)
Storage temperature -40 to 70°C (with no icing)
Surrounding air operating
25% to 85%

*1. When using a 24-VDC power supply voltage, there will be an inrush current of approximately 0.5 A.
     Allow for this inrush current when turning ON and OFF the power supply to the Timer with device with a solid-state output,
     such as a sensor.
*2. DC ripple: 20% max.
*3. The power consumption is the value after the Timer times out.


Accuracy of operating
±1% of FS max. (±1% ±10 ms max. at 1.2-s range)
Setting error ±10% of FS ±0.05 s max.
Influence of voltage ±0.5% of FS max. (±0.5% ±10 ms max. at 1.2-s range)
Influence of
±2% of FS max. (±2% ±10 ms max. at 1.2-s range)
Insulation resistance 100 MΩ min. at 500 VDC
Dielectric strength Between charged metal part and operating section:
2,900 VAC 50/60 Hz for 1 min.
Between control output terminals and operating circuit:
2,000 VAC 50/60 Hz for 1 min.
Between contacts not located next to each other:
1,000 VAC 50/60 Hz for 1 min.
Impulse withstand
test voltage
5 kV between power terminals,
7.4 kV between conductor terminal and operating section
Noise immunity Square-wave noise generated by noise simulator
(pulse width: 100 ns/1 μs, 1-ns rise): ±1.5 kV
Static immunity Malfunction: 4 kV, Destruction: 8 kV
Destruction 0.75-mm single amplitude at 10 to 55 Hz for 2 h each in 3 directions
Malfunction 0.5-mm single amplitude at 10 to 55 Hz for 10 min each in 3 directions
Destruction 1,000 m/s2 3 times each in 6 directions
Malfunction 100 m/s2 3 times each in 6 directions
Mechanical 10 million operations min. (under no load at 1,800 operations/h)
Electrical 100,000 operations min. (5 A at 250 VAC, resistive load at 360 operations/h)
Degree of protection IP30 (Terminal block: IP20)
Weight Approx. 100 g

Relation between H3DT Ambient Temperature and Mounting Interval (Reference Values)

The relation between the ambient temperature and mounting interval is shown in the following graph.
If the Timer is used at 55°C or higher with a mounting interval that is smaller than that shown in the following diagram, the temperature inside the Timer will increase, reducing the life expectancy of internal parts.

H3DT-A Specifications 5

Applicable standards

cULus: UL 508/CSA C22.2 No. 14
EN 61812-1: Pollution degree 2, Overvoltage category III
CCC: Pollution degree 2, Overvoltage category II, section GB 14048.5
LR: Category ENV1.2
DNV GL (Temperature B, Humidity B, Vibration A, EMC A, Enclosure A)
EMC (EMI) EN 61812-1
Radiated Emissions: EN 55011 class B
Emission AC Mains: EN 55011 class B
Harmonic Current: EN 61000-3-2
Voltage Fluctuations and Flicker: EN 61000-3-3
(EMS) EN 61812-1
Immunity ESD: EN 61000-4-2
Immunity RF-interference: EN 61000-4-3
Immunity Burst: EN 61000-4-4
Immunity Surge: EN 61000-4-5
Immunity Conducted Disturbance: EN 61000-4-6
Immunity Voltage Dip/Interruption: EN 61000-4-11


Input None
Output Control output The output is turned ON/OFF according to the operating mode when
the value that is set on the dial is reached.