Patent GB-600806-A (GB)
Title: Totalising means for use with a group of electricity measuring instruments
IPC: G08C13/02
Filed: 1944-05-22
Abstract: 600,806. Supply meters. CHAMBER LAIN & HOOKHAM, Ltd.. JAMES, S., WEBB, E. A., and BRAINES, W. F. May 22, 1944, No. 9835. [Class 37] In a system for totalising the impulses received from the fastest running of a plurality of electricity measuring and impulse transmitters, the impulses from a predetermined one of the transmitters plus those in excess from a faster running transmitter are totalised. by means of relays associated with and responsive to impulses transmitted, contacts of these relays controlling the locking and unlocking of additional relays for determining which of the impulses are to be registered. The transmitters are restricted to certain speed' relationships disclosed in the specification. As shown, a K.V.A. maximum demand indicator A is adapted to register all the successive impulses derived from a K.V.A. hour meter a plus excess impulses from either or both of similar K.V.A. hour meters b, c, subject to the speed restrictions mentioned below. Each meter a, b, c has contacts a<1>, b<1>, c<1> which are closed intermittently at a rate dependent on the actuation of the meters. Relays d, e, f are provided for opening the contacts a<1> .. c<1> respectively, and for controlling locking relays h, m, p, and maintaining relays g, l, n appropriate to meters a, b, c. An additional locking relay k and maintaining relay j are provided in respect of meter a. In operation, assuming that meter a is running faster than b which is faster than c, and that all relays are in their inoperative position shown, the first closure by meter a, of contacts a<1> energises relay d over contacts a<1>, e<2>, f<2> from current supply lines B. Contacts d<1> change over to disconnect the energising circuits of relays e, f and at the same time permit an impulse to be transmitted to and registered by the maximum demand indicator A. Over contacts e<2>, f<2>, d<3>, g<2> relay h is energized. Over contacts d<2> the coil a<2> in meter a is energized, and releases the contact a' whereupon relay d de-energizes. As contacts d<3> open, relay g, previously short circuited by contacts d3, energizes in series with relay h over contacts h<1>. The next closure of contacts a' in meter a results in a similar actuation of relay d to send an impulse to the demand indicator A and in the locking of relays k, in series over contacts k<1> as relay d falls off. Assuming now meter b actuates contacts b', relay e is energized over contacts d<1>, b<1>, f<2> and contacts e<2> change over to energize the release coil b<2> for contacts b'. Contacts e<1> change over to short circuit relay k over contacts g', j<1> so that both relays k, j release. Over contacts e<3> relay m is energized and when contacts e<3> are released relay l energizes in series with relay m. No impulse is sent to the indicator A, however, since relay g is still energized. As meter a is assumed to be running faster than b, contacts a' will close again before a further actuation of b' and result in re-locking of relays k, j and actuation of indicator A as above described. The second impulse from meter b will unlock relays k, j, and lock relays n, p. In a similar manner the first impulse from meter c will unlock relays n, p. Thus all impulses from meter a are registered and all impulses from meter b unlock relays j, k locked by meter a, and lock relays n, p, unlocked by meter c. Since meter a is running faster than b relays g, h or g, h, j, k, will always be energized when meter b sends its impulse. Similarly since meter b is running faster than c relays l, m, or l, m, n, p will always be operated when meter c sends its impulse. Only the impulses from meter a will therefore be registered. Should meter b now run faster than a, and c, the condition as between meters b, c remains unchanged. Meter b will now, however, unlock relays j, k and also g, h, and for all impulses sent by meter b in excess of the number sent by meter a, relay e will send an impulse to the maximum demand indicator A over contacts e<1>, g'. Similarly, should meter b run faster than a and meter c faster than b those impulses sent by meter c in excess of those sent by b will be registered on the maximum demand indicator A by impulses over contacts f <1>, l<1> since both circuits containing relays n, p and l, m will be unlocked. Since the relays d, e, f complete their circuits through contacts of the other two, only one of these relays can operate at a time. Thus impulses from the meters a, b, c arriving simultaneously are separated into distinct operations. For this purpose the duration of closure of contacts a<1> ... c<1> is made long enough to allow the impulses to be delayed by the operation of one or more of the relays associated with the other meters. The relays j, k and n, p may be dispensed with. The meters are precluded from running at relative speeds other than those indicated above. Thus meter c cannot run faster than b but slower than a. Four or more meters may be used.