Food Cart Gramma Plug


A cart with hot food for patients has a long path to go from the hospital kitchen to a specific department. Meanwhile, the food might cool down. And it can take even longer until the food reaches the last patient in the department. Is this really the way things must be, serving cold food on Shabbat?

 It is generally accepted that it is very important for patients to be served hot food. It is true that not all patients in a hospital are considered to be in mortal danger, but a public institution cannot differentiate between one patient and another. Thus, as a general rule, all the patients should receive hot food. But how can this be done on Shabbat?

 This question of transporting and handling hot food and how to do it on Shabbat is relevant not only for hospitals but also for homes for the elderly with full care facilities or institutions for the infirm, whose residents are halachically defined as being ill.

 The solution provided by The Zomet Institute for such situations is based on gramma (indirect action), which is permitted on Shabbat under these circumstances. But a practical problem still remains: How can an individual patient who needs hot food be sure that the nurse or the nurse's aid who was in charge of bringing the food and keeping it warm actually used the gramma mechanism? Usually gramma devices are operated by people who want to avoid desecrating Shabbat, but in the case of food the "operator" and the "user" are not the same person.

 Since the above question was raised by the religious department of the General Health Service, The Zomet Institute studied the principles involved. The solution is an automatic gramma outlet. The food carts in interested institutions are outfitted with a plug that fits a special electrical outlet, not a standard one, so that it cannot be plugged into regular sockets. Most of the time, the circuit in this special outlet is not live, both during the week and on Shabbat. The equipment (hidden in the wall) has an electrical mechanism that operates as follows:

 A digit is displayed on a wall panel, cycling through the numbers 0 to 9, with the value changing every half minute. Every five minutes, at the instant that the number changes from 0 to 1, an internal electronic test is performed (with a duration of about 1 millisecond) to check whether something has been inserted into the plug (by measuring the resistance on the line). If the test shows that the outlet is "occupied" (by a plug for a food cart or for any other electrical device) the current will be turned on, and the food will be heated. The numbers on the panel continue to cycle, and the heating continues. That is, in each cycle, the food is warmed for four and a half minutes and is not warmed for half a minute (while the 0 is shown on the panel). The heating cycle continues as long as the wire remains in the plug.

 The worker puts the plug into the socket and goes on to other tasks. When the number in the panel changes from 0 to 1, the mechanism "senses" the plug and connects the electric circuit for the next four and a half minutes, corresponding to the changing digits.

 A worker who observes Shabbat will be careful to disconnect the food cart from the socket only when the digit 0 is shown on the display (when the current is off). But even if the worker desecrates the Shabbat, the food is not forbidden to the patient, since it was heated in a permitted way. The fact that the current might have been turned off in a prohibited way does not have any effect on the food.

 Does this sound too complicated? Don't worry! All that is needed is a sign with the following simple instructions: "On Shabbat, the plug can be inserted at any time. It should be disconnected only when the digit 0 is showing." That's all there is to it!

 A food cart is only one example of many devices in the medical field that can be operated in this way. But note: this is only appropriate for medical equipment, which is needed for essential functions. It cannot be used for home appliances, since it is usually quite easy to get along without them on Shabbat.

 For details and further clarification, contact The Zomet Institute.

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