Four Relays 10A/240V
8-Layer Stackable Card
for Raspberry Pi


This product has been discontinued. It is being replaced by the “4-Relays 4-Inputs” card, which in addition to the four, 8A/240V relays has four universal, opto-isolated digital inputs and an RS485 port.

  • Four RELAYS with Status LEDs
  • Eight layer stackable to 32 relays
  • Pluggable Connectors 30-16 AWG wires
  • NO and NC contacts on all relays
  • Switch loads of up to 10A and 240V
  • Software self-test
  • Command Line and Python Drivers

Out of stock


Raspberry Pi Relays: Add up to 32 heavy duty loads of up to 10A and 240VAC to your Home or Industrial Automation Projects

Perfect add-on to your project when you have to control large number of heavy duty AC loads. Stackable to 8 layers, the card can add up to 32 relays to each Raspberry Pi in a very compact form factor.

Pluggable connectors make the 4-RELAYS card easy to use when multiple cards are stacked up.  All relays have Normal Open and Normal Close contacts and can switch up to 10A/240VAC. Status LEDs show when relays are on or off. If  you need to switch DC loads of more than 24V, our 8-MOSFETS card can handle up to 240VDC.


The card is compatible with all Raspberry Pi versions from Zero to 4. All stacked cards share the I2C bus using only two of the Raspberry Pi’s GPIO pins to manage all eight cards.  This feature leaves the remaining 24 GPIOs available for the user.


  • Electrical endurance: minim 105 cycles at 1,800 operations per hour, full load
  • Mechanical endurance: minim 107 cycles at 18,000 operations per hour, no load


The 4-RELAY card needs 5V to operate and can be powered from Raspberry Pi or from it’s own 2.1mm barrel connector. The relay coils are also powered from the 5V.  The card draws 10mA with all relays off. Each relay needs about 80 mA to turn on. If power is applied to the barrel connector, no other power supply is needed for the Raspberry Pi.


You can control the 4-RELAY card by writing your program in the language of your choice using the Command Line system, or the Python Driver.  Browser control is very easy using the Node-Red node we provide. NEW: CODESYS Driver with sample code.


The 4-RELAYS card can be tested before installation by running a simple command from the command line. The card will cycle each relay on and off at 0.5 seconds interval. The clacking noise of the relays and the lighting of the LEDs will assure that all relays are functioning.


Up to eight 4-RELAY cards can be stacked on your Raspberry Pi. Each card is identified by jumpers you install to indicate the level in the stack. Cards can be installed in any order. The three position jumper on the upper right corner of the card selects the stack level. For your convenience, two jumpers are provided with each card. For complex Home Automation tasks you can add to the stack one or more Home Automation cards with analog and digital inputs and outputs.


User’s Guide and Schematics of the 8-RELAYS card can be downloaded from our website.


Install your Raspberry Pi and up to eight 8-RELAYS cards parallel to the DIN-Rail using our  DIN-RAIL Kit Type-1. Install the whole assembly  perpendicular to the DIN-Rail using the DIN-RAIL Kit Type-2.


  • 4-RELAYS add-on card for Raspberry Pi
Raspberry Pi Relays, Heavy Duty
Raspberry Pi Relays, Heavy Duty
  • Mounting hardware
    • Four M2.5x18mm male-female standoffs
    • Four M2.5x5mm screws
    • Four M2.5 nylon nuts

Mounting Hardware

  • Two Jumpers

2 Jumpers

  • Four 3-pin female mating connector plugs

Heavy Duty Pluggable Connectors


  1. Plug your 4-RELAYS card on top of your Raspberry Pi and power up the system.
  2. Enable I2C communication on Raspberry Pi using raspi-config.
  3. Install the 4-RELAYS software from
    1. ~$ git clone
    2. ~$ cd /home/pi/4relay-rpi
    3. ~/4relay-rpi$ sudo make install
  4. ~/4relay-rpi$ 4relay

The program will respond with a list of available commands.

Additional information

Weight120 g
Dimensions10 × 7 × 2 cm

4 ea. 10A/240VAC





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8-Layer Stackable Card
for Raspberry Pi”