# Relay module with delay, HCW-M421, adjustable time, display, 6–30V

> Delay relay timer module with adjustable time, digital display, powered via 5V MicroUSB or 6-30VDC through screw terminals. Selectable time resolution (0-99.9s, 0-999s, 0-999min), 4 operating modes (delay, pulse, ON/OFF cycle). 5A relay output for DC or AC loads, closed-open contact type. Signal trigger High Level 3-24V. Dimensions 62 x 38 x 17mm.

- Page: https://sigmanortec.ro/en/delay-relay-module-adjustable-time-display-6-30v
- Price: 18.98 RON
- Availability: In stock; 1-2 zile
- Reference: 33573 · EAN: 5949412377865
- Category: Electronic components > Timer Modules
- Specifications: Supply Voltage: 6; Maximum Input Voltage: 30; Output Type Voltage: Closed-Open Contact; Input Voltage Type: “DC” in Romanian can mean **“de ce”**, which translates to **“why”** in English.
- Package (shipping data): 0.026 kg
- Updated: 2026-10-13
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 02:52 (Europe/Bucharest)

## Description

Adjustable delay relay module, ideal for automation and timed controls, has a digital display for quick setup and monitoring, is flexibly powered at 5V via MicroUSB or 6-30VDC at the terminals, offers selectable resolution down to tenths of a second and includes 4 operating modes for delay, pulse, or ON/OFF cycle, 5A relay for DC or AC loads.
The HCW-M421 delay relay module is a programmable timer with a display, used to control an external load after an adjustable time interval or after a cycle of repeated on and off operations. It receives an external High Level trigger signal or can operate independently, directly from the power supply, making it suitable for automation, delayed starting or stopping of pumps, solenoid valves, lighting, motors, chargers, and other equipment that requires timing or cyclic operation.
The accepted trigger signal is High Level, with a voltage between 3 and 24 V, optically isolated from the rest of the circuit for stable operation in environments with interference. The module offers 7 operating modes (P1.1, P1.2, P1.3, P2, P3.1, P3.2 and P4), each using combinations of the OP (activation time), CL (deactivation time), and LOP (number of repeated cycles, between 1 and 999 or unlimited) parameters. Time is set with 0.1-second resolution, in the ranges 0 - 99.9 seconds, 0 - 999 seconds, or 0 - 999 minutes, selected by the decimal point position on the 3-digit display.
Among the main features are the output relay with NO, COM and NC contacts, the 3-digit digital display, the four control buttons STOP, SET, UP and DOWN, the MicroUSB connector, and screw terminals for power supply and trigger signal. Power is supplied either at 5 VDC via the MicroUSB port, or at 6 - 30 VDC via the screw terminal, with the two power supply methods usable alternatively.
Thanks to the High Level trigger signal between 3 and 24 V, the module can be controlled directly from the digital outputs of boards such as Arduino, ESP32, STM32 or Raspberry Pi, and through the relay contacts it can also operate equipment connected to a PLC or to the 220 VAC mains.
Specifications:
Model: HCW-M421
Supply voltage: 5 V via MicroUSB or 6 - 30 VDC via screw terminal
Trigger signal: High Level, 3 - 24 V, optically isolated
Output control: Relay with NO / COM / NC contacts, max 30 VDC 5 A or 220 VAC 5 A
Current consumption: approximately 20 mA at rest, 50 mA in operation
Time resolution: 0 - 99.9 seconds, 0 - 999 seconds, 0 - 999 minutes
Operating modes: P1.1, P1.2, P1.3, P2, P3.1, P3.2, P4
Program parameters: OP (activation time), CL (deactivation time), LOP (number of cycles, 1 - 999 or unlimited)
Relay lifespan: over 100,000 cycles
Operating temperature: -40 - 85 degrees Celsius
Parameter memory: settings are retained after power loss
Time display: Depending on the batch, the time can be displayed in ascending order, from 0 to the set value, or descending, from the set value to 0
STOP button control: Relay enable/disable and display switching between C-P mode (turns off after 5 minutes) and O-d mode (always on)
Dimensions: 62 x 38 x 17 mm
Pinout:
Connector
Pin
Function
Power block (screw connector)
+
Power supply 6 - 30 VDC
Power block (screw connector)
Power ground (GND)
Trigger block (screw connector)
IN
Trigger signal, High Level 3 - 24 V
Trigger block (screw connector)
G
Trigger signal ground
MicroUSB
5V / GND
Alternative 5 VDC power supply
Relay output block
NO
Normally open contact
Relay output block
COM
Relay common terminal
Relay output block
NC
Normally closed contact
Program
Submode
Behavior
P1
P1.1
On signal, the relay activates and remains on for OP, then deactivates. A new signal received during OP is ignored.
P1
P1.2
On signal, the relay activates and remains on for OP, then deactivates. A new signal received during OP restarts the OP countdown.
P1
P1.3
On signal, the relay activates and remains on for OP, then deactivates. A new signal received during OP immediately stops the relay and the countdown.
P2
On signal, the relay remains off for CL, then activates for OP, after which it deactivates.
P3
P3.1
On signal, the relay enters an ON (OP) / OFF (CL) cycle, repeated LOP times; a new signal stops the current cycle.
P3
P3.2
At power-up, without requiring a signal, the relay automatically enters an ON (OP) / OFF (CL) cycle, repeated LOP times.
P4
The relay remains active as long as the signal is present. When the signal disappears, the OP countdown begins, after which the relay deactivates.
Usage:
Warning: the relay output contacts can switch 220 VAC mains voltage, which is dangerous to touch; connections on the 220 VAC side must be made only with the load disconnected from the mains, by a qualified person.
Power the module either through the MicroUSB port at 5 VDC, or through the left screw terminal at a voltage between 6 and 30 VDC, observing the indicated polarity.
Connect the load to the output connector using COM and NO for a device that should be powered when the relay activates, or COM and NC for one that should be powered permanently and interrupted when the relay activates.
Connect the trigger signal between 3 and 24 V to pin IN and the signal ground to pin G, or manually short the two terminals for a quick test, where the selected mode requires an external signal.
Select the operating mode by holding SET for 2 seconds on the main screen, then choose the desired mode (P1.1 - P4) with the UP and DOWN buttons.
Briefly press SET to set the available parameters in the selected mode (OP, CL and LOP), adjusting each value with the UP and DOWN buttons; holding the button allows fast adjustment.
Press STOP during setup to choose the decimal point position and the desired time range, for example display 03.2 corresponds to a value of 3.2 seconds.
After finishing the settings, hold SET for 2 seconds to save the values and return to the main screen.
Briefly press STOP on the main screen to enable or disable relay operation without changing the previously set program and parameters.
Hold STOP for 2 seconds to switch between C-P mode, in which the display turns off after 5 minutes of inactivity, and O-d mode, in which the display remains always on.
Do not exceed the maximum current and voltage allowed by the relay contacts, namely 30 VDC 5 A or 220 VAC 5 A, and do not touch the output terminals while the module is powered.
For stable trigger signal operation, use short cables between the signal source and pins IN and G, especially in environments with high electrical noise.