UM0277

Getting started

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3.4

Getting started

Warning:

The Kit is not electrically isolated from the AC input. The MCU

is directly linked to the mains voltage. No insulation is

ensured between the accessible parts and the high voltage.

The STEVAL-IHT001V1 Kit must be used with care and only

by persons qualified for working with electricity at mains

voltage levels. All measurement equipment must be isolated

from the mains before powering the board.

When using an oscilloscope with the Kit, it is safer to isolate

it from the AC line. This prevents a shock from occurring as a

result of touching any SINGLE point in the circuit, but does

NOT prevent shocks when touching TWO or MORE points in

the circuit.

To operate the STEVA-LIHT001V1 board correctly, use the following procedure:

●

Connect the NTC thermistor to the “NTC” connector on the thermostat board.

●

Connect the DOOR switch (if you use an external door switch) to the “Door” connector

on the thermostat board

●

Push the board “Door” switch to the “Close” position in order to allow “temperature

selection” push-button operation

●

Connect the loads on the thermostat board:

–

Compressor to “MOTOR” connector

–

Defrost resistor to “DEFROST” connector

–

Light bulb to “LIGHT” connector

●

In case of control with a computer (using the GUI), please go to Section 2.3.3:

Capacitive power supply).

●

Apply the mains wire to the “MAINS” connector. Plug this wire to the mains voltage.

●

After a few seconds:

–

The “ON/OFF” green LED must light ON

–

The “medium” red LED must light ON

–

The compressor switches ON if the sensed temperature is above the temperature

order (should be the case if the NTC thermistor is at ambient temperature).

–

The Light Bulb is switched ON if the DOOR switch is on “open” position.

●

Troubleshooting:

–

If no LED is ON: replace the fuse.

–

If LEDs seem OK, unplug the board from the mains. Discharge the VDD supply

with a short-circuit between VDD and GND. Plug back the board to the mains.

Note:

The temperature order can be changed using the BP1 push button on the thermostat board.

Each time the BP1 push button is pressed, the red LEDs light on alternatively.

Note:

If the “Door” Switch is in “Open” position or if the fridge door is opened, the temperature

order cannot be changed from the thermostat board (only by using the GUI software).