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24 Sivan, 5782 - June 23, 2022 | Mordecai Plaut, director Published Weekly










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The Vaad Mishmeres HaShabbos visits the Rosh Hayeshiva shlita

by C. Honig

At the home of the Rosh Yeshiva shlita

An impressive gathering designed to bolster and clarify the laws of Shabbos in our times took place in the home of the Rosh Yeshiva HaRav Gershon Edelstein during which various poskim and rabbonim and heads of Mishmeres HaShabbos came and to deal with strengthening the fortifications of Shabbos.

The gathering was attended by HaRav Shimon Galai, HaRav Sariel Rosenberg, HaRav Yisroel Weisel, HaRav Shmuel Dovid Reisner and HaRav Elimelech Kornfeld.

The keynote address was delivered by Maran, who noted, "It is a great merit and privilege to be involved in preventing Shabbos desecration and strengthening Shabbos observance. Shabbos is the source of blessing, and all those involved in this area are benefiting the public by increasing the sanctity of Shabbos and preserving it. This also has an impact on the entire surroundings."

The main talk was by HaRav Eliahu Beifus, head of the Mishmeres Shabbos. His main topic was that of water pumps in modern buildings.

Among other things, he explained that every pump has a water supply (a reservoir) in its respective building so that every activation causes water to rise from that source. He went into detail explaining that many pumps are now of the inverter type whose function is regulated exactly according to the usage of water. This operates on an electric frequency.

In recent years, in tall buildings, a change has taken place in the form of water supply. The municipal water pressure is sometimes not sufficient to pump the water to the higher floors. To accommodate this problem, large tanks of water, are built in the basements which are filled from the municipal network. In addition the building's pump supplies the local pressure. The pressure pump does not work nonstop but rather according to the usage. Modern sensors are very fast and accurate and they are used for constant monitoring of the system.

When a resident opens a tap, the water pressure decreases, activating the pump. When the residents do not use water, the pressure in the pipes increases and the pump stops working.

While in the past, the pumps operated on an ON-OFF system (that is they either worked or they did not), today, most pumps are built with a permanent pressure system using an inverter motor which enables a steady water pressure by constantly adapting the pace of the motor's rotation according to real time usage.

Such pumps operate via a digital pressure sensor. As the water pressure decreases, the motor accelerates, and shuts down when there is no demand. When it operates, every slight movement affects the motor which can cause it to operate on a higher or lower level.

The rabbonim discussed the halachic implications of the differences between the two kinds of pumps, since even when the pump is activated, there is a difference between the two. A regular ON-OFF pump is not necessarily affected by a random opening of a faucet while the inverter model is able to increase or decrease its power according to need, thus preserving a constant water pressure all the time.

The rabbonim of Mishmeres HaShabbos presented the solution developed by them which involves installing a special device upon the pump systems of high rise buildings based on inactivating the pressure sensor and which also shuts off any electric faucet designed to fill the tank. The pump then operates on a steady level. In addition, the water in the tank is replenished the same way as in a home lavatory, through a mechanical float.

In the discussion it was emphasized that while there is no price that can be placed on Shabbos observance, nevertheless the device suggested by Mishmeres HaShabbos is affordable when divided among the neighbors but even more so when it is installed during construction of the building.

On old version of the Mishmeres HaShabbos booklet (5774) discussing Refrigerators and Digital Water Meters is available click here.

This booklet includes a critical discussion of the Star-K Shabbos mode for refrigerators and stoves.


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