A letter from our gedolim and poskim was published last week forbidding the used of digital refrigerators and freezers (i.e. most such appliances currently sold) on Shabbos without neutralizing the effect of the user upon electrical and digital registering. After its publication and in light of the thousands of calls to clarify the problem and its solutions, the Mishmeres HaShabbos wishes to clarify the central point of this halachic prohibition and the various possible solutions thereof.
The temperature in every refrigerator changes significantly and immediately upon the opening or closing of its door. The thermostat of mechanical refrigerators has only two states: ON or OFF. When a person opens the door when the thermostat is in the OFF mode and the compressor is not working, nothing will happen until the thermostat goes into the ON state and the circuit is closed. If one opens the door when the circuit is closed and the compressor is working, he only causes the compressor to operate a little longer. With the new digital refrigerators and freezers, the temperature sensors are built in a way that the electricity flows to the control card with every change in temperature.
The control card works like a small computer with millions of electric circuits some of whose conductivity changes all the time. The electrical current reaching the card is translated into digital impressions according to the specified arrangement of the electrical circuits and according to these impressions, the control card operates the refrigerator.
This is why every opening or closing of the digital appliances cause a direct and immediate electricity flow and digital registrations on the digital thermostat and control card.
The halachic solutions for the use of the digital appliances on Shabbos as determined by the Mishmeres HaShabbos are:
1) To put them on a Shabbos clock that ensures that they operate only intermittently and to open them on Shabbos only when they are cut off from the electric mains;
2) To buy Beko (brand) appliances sold in Israel which have the Badatz Eida Chareidis hechsher which can be opened at will;
3) To install the Mishmeres HaShabbos adapter which is compatible with over 500 models of refrigerators which allow free use.
All of these solutions require locking the buttons in the doors of refrigerators and freezers.
The phone number of the Mishmeres HaShabbos office whereby one can verify the type of their appliance, if mechanical or digital, or to order compatible adapters: 0722-164422. Fax: 072-2164423. Email: a0722164422@gmail.com
A detailed explanatory pamphlet (in Hebrew) is available upon request from: chashmal052@gmail.com
