Howard Butler Ltd

These isolators isolate the DC Input signal from the DC Output signal, which is directly proportional to the input signal. There are two levels of isolation offered, the M100-DA1/DV1/DV2 have 4kV isolation and the M100-DA11/DV11/DV21 have 1.5kV isolation. A wide range of both D.C. Current and voltage inputs are offered. Typically these isolators can be used to prevent earth loops which occur when a measuring source that is earthed, is connected to a computer or data logger that is also earthed. Another common use is to provide isolation on the inputs to a PLC. All of these isolators have either A.C. or D.C. auxiliaries which means that they have an advantage over loop powered units, in that if for any reason the output lead should become disconnected, the input will not be saturated.

The M100-DS series of summation transducer take up to four inputs and provide an output signal directly proportional to the sum of the inputs. A typical application is the summation of total kW of four seperating generating sets e.g. the four individual kW readings are provided by M100-WA4 transducers with 0-1mA output signals. The M100-DS4 summates the four 0-1mA signals and provides a single output signal that is directly proportional the sum of the total kW of all four generators. It is important to note the following when using summation transducers: to ensure the correct reading is obtained. The current and voltage ratios must be identical otherwise the subsequent summation will be meaningless.

The M100-DI1 is a linear integrator which accepts D.C. inputs and integrates the input with respect to time. An output is provided via a relay which gives a pulsed output, the frequency of which is directly proportional to the amplitude of the input signal. One of the main uses of the M100-DI1 is the measurement of Watt and Kilowatt hour. This is achieved by feeding the output of a watt transducer (M100-WA series) into the M100-DI1. The input signal is integrated against time and the resulting output pulses from the relay are proportional to the kW.h being consumed. These pulses can then be fed to an electromechanical counter, digital counter or a computer, where the kWh consumed can be stored. Another se is the measurement of Ampere hours The M100-DI2 is the same as the M100-DI1 with the additional feature of having 2 relay outputs, this allows the user to feed one set of pulses to a counter on a switchboard whilst feeding the other ser of pulses to a remote computer in a control room.

DC Shunts supplied by Howard Butler Ltd

Here at Howard Butler we manufacture instrumentation and control products including:

• Current transformers
• Power meters
• Digital panel meters
• Transducers

For over 100 years we have been manufacturing in the UK and we export worldwide. Please visit our website or contact us for more information.

96 x 48mm digital panel meters with 3.5 digit, 14.2mm high 7 segment LED's. The products offer a wide range of AC or DC input parameters. Essentially there are 3 main product group types:- AC Volts, Amps, Milliamps, DC Volts, Amps, Milliamps, Millivolts, Frequency. With the combination of mA input M300-AD1 and the M100 series Power transducers, parameters such as kW, kV, Ar etc can be measured and displayed. Customer adjustment of botjh "ZERO" and "SPAN" is permissible via potentiometers, accessible from the rear of the product.

Earth Leakage Protection Equipment supplied by Howard Butler Ltd

Variable Earth Leakage Relays in compact 35mm din rail mounting cases for use on 3 phase electrical systems. To monitor earth leakage current and to operate an associated relay at a preset current. May be used to shut down a system or operate an alarm under fault conditions.

Two split-core current transformers with four or five built-in current ratios in one product. Suitable for use up to 1000A using cable primaries. The split-core design allows installation into existing networks without disconnecting cables or busbar circuits. The multi-ratio feature is ideally suited to stockists, distributors and contractors who need instant access to popular CT ratios up to 1000A in two stock items.

Energy Power Metering Systems supplied by Howard Butler Ltd