Howard Butler Ltd

range of ring type Split-Core Current Transformers. The products are tape wrapped and are complete with 1 metre length flying leads. Primary ranges are available up to 3000A and 5A secondary. Suitable for various cable sizes. For installation into existing networks. The split-core allows installation without disconnecting cable or busbar circuits.

The M100-RTD monitors the resistance of either 100 Ohm platinum or 120 Ohm Nickel. The RTDs resistance increase as the temperature rises, this resistance change is detected by the M100-RTD, which provides an output corresponding to the temperature being measured. The temperature versus resistance values are provided by the supplier of the RTD used. RTD measurement of temperature is used in large transformers and large motors to ensure winding temperatures do not rise to a level that would change the winding.

Two rotary arm switches for switching of ammeters (4 position) and voltmeters (7 position). Suitable for panel builders requiring a panel mounted switch for switching meters between phase currents or line & phase voltages.H30

A range of compact low cost moulded case current transformers suitable for primary currents from 1A to 50A with built in terminal covers and M6 screw terminals for primary current connection.

The M100-AX1 and AX3 are essentially the same as the M100-AA1 and AA3, but they have auxiliaries which allows the working range to be between 0-125% rather than 10-125%. Used where the average sensing of current is required from 0-125% of the nominal current. The M100-AAS and M100-ALS are A.C current summation transducers. Both can have up to 3 inputs of either 1,5 or 10 amp. These inputs are summed by the transducer and one D.C. output is provided, which is proportional to the sum of the inputs. The M100-AAS is self powered with a range of 10-125%, the M100-ALS is auxiliary powered and provides a 4-20mA output with a working range of 0-125%. Typical application is to measure the total current in a 3 phase system and display it via one meter. For example, if a 3 phase system has 3 current transformers 2500/5 then a moving coil meter could be connected to a M100-AAS scaled 0-7500. Note the C.T's must all have the same ratio or the output from the transducer will not be the sum of the total current in the system.

DIN rail mounting transducers available in 55mm x 112mm or 100 x 112mm DIN rail cases. Used to convert various inputs into standard DC signals for driving panel meters and for use in control devices.

Highly accurate manganin resistance d.c shunts. When a current is passed through the shunt a proportional millivolt output is produced. The products detailed in this production are our standard range, but for quantity orders, HOBUT engineers will be pleased to work with customers to design individual shunts to their specifications.

Split Core Transformers supplied by Howard Butler Ltd

Highly accurate manganin resistance d.c shunts. When a current is passed through the shunt a proportional millivolt output is produced. Our standard range of BS89/IEC51 class 1 or class 0.5 shunts can be current rated from 5A to 10000A with 50mV to 300mV output.

Switches - Voltage Selector supplied by Howard Butler Ltd