The programmable electronic current burden, type 3691 is designed for efficient testing of current instrument transformers. It replaces traditional burdens which are built with passive resistances and inductances.
The wide range of programmable impedances enables the emulation of prevalent national and international standard burden values as well as customer-specific values.
The electronic current burden constantly monitors the applied burden accuracy and indicates any burden parameter deviation that may occur when testing an instrument transformer for accuracy, thereby connection and handling errors in the complete accuracy test sytem are minimized.
The instrument is protected against user setting errors, overcurrents, overvoltage and overheating. The error messages are indicated on the dot matrix display installed on the front panel of the device.
In conjunction with the type 2767 automatic instrument transformer test set, the burden can be integrated into a computer-controlled test system.
For applications requiring apparent powers higher than 75 VA, the remotely controlled additional external passive current burden type 3692 expands the power range of the programmable electronic voltage burden type 3691 to 200 VA.

Advantages
• High versatility – 3691 is a universal and standardized current burden offering a wide burden spectrum. The built-in test frequency detection and auto-selection eliminates the disadvantage of having one instrument per power frequency value
• Accuracy at best level – 3691 + 3692 units are prepared for accuracy testing of current instrument transformers with most stringent accuracy requirement – These units are qualified for use in metrology institutes
• Configuration flexibility – Unit replacement is not necessary when power expansion is required, quick and easy unit extension is available with type 3692
• Optimized investment – Many classical passive burdens can be replaced by a single electronic current burden type 3691
• Compatibility – Unit can be integrated with a variety of instrument transformer test sets, such as types 2767/63, 2761, 2711/22, or other makes
• Upgradeable to an automatic test system – By combination with a device type 2767 or 2763
• Optimized setting time – Unit can be quickly and easily configured for a new test using pre-defined burden values from applicable standards or user defined set of values

Applications
• Current instrument transformers (LV/MV/HV)
• On-site testing of high voltage instrument transformers
• Metrology institutes
• Research and development