Sigma Load Bank Control Explained

SIGMA is a multifunctional embedded load control system specifically designed for Avtron load banks. SIGMA is the leader in simplicity, ease of use and accuracy. SIGMA brings market-leading solutions to today’s power testing requirements which can require high-level instrumentation, data capture and verification. SIGMA is currently available in two forms each with various control interfaces.

SIGMA LT Control

SIGMA LT is an entry-level control system for selected 2000, 3000 and 5000 purely resistive load banks. It provides simplistic load test capabilities for single and networked load banks. SIGMA LT has two user interfaces:

Digital Toggle Switches

Digital toggles are fitted as standard to all SIGMA LT load banks and provides local control. Digital toggles are perfect for fast load testing when a SIGMA LT hand-held is unavailable. The digital toggle switches provide 3 phase instrumentation on a seven segment LED display located on the load bank.


The SIGMA LT Hand-held is an optional touchscreen remote control that allows the user to utilise all SIGMA LT features and benefits. 25 SIGMA LT load banks can be connected in a network and controlled by a single hand-held. The hand-held allows individual load bank control and total network control with the ability to capture load test data to a USB flash drive.

SIGMA 2 Control

SIGMA 2 is fitted as standard to all 3000, 6000 and 8000 series load banks and can be specified on the majority of other Avtron load banks. SIGMA 2 is the most comprehensive load bank control with high-level instrumentation and data acquisition with a range of user interfaces for any load test application. SIGMA 2 interfaces include:


The hand-held is housed in a robust aluminium enclosure and provides remote testing options for SIGMA 2 load banks. It can control up to 14 resistive, inductive or capacitive load banks and displays three phase instrumentation on a full-colour screen. The hand-held allows an operator to work in kW, kVA or KVAr (depending on type of load bank connected), percentage of the supply-on-test and perform customised automatic tests.

PC Software

SIGMA PC Software is the most comprehensive and advanced load bank control Avtron offers. SIGMA PC software is a Windows™ based alternative to the Hand-held. It provides further enhanced load control along with transient speed instrumentation, full data acquisition reporting with graphical displays, real-time data such as recovery times and % errors necessary for testing to diesel gen-sets to ISO8528.

PC Basic

SIGMA PC Basic is a simplified version of the PC software. PC basic offers control of up to 42 SIGMA 2 load banks with an intuitive user interface, graphical display and data capture capabilities. PC basic is a cost-effective solution for PC based load bank control.

Network Pro

SIGMA Network Pro is Windows™ based load test software specifically developed for hyper-scale data centre load test applications. It uses a specially designed gateway to connect and control 200+ SIGMA LT and/or SIGMA 2 load banks in a single network. Network pro allows individual, grouped or total network control with configurable ID’s to ensure organised and accurate testing when controlling many load banks.

Site Load Correction

Site load correction is used for maintaining diesel generating sets and alleviate the harmful effects associated with light loading. Externally mounted current transformers monitor load from the gen-set to the site and apply load when the gen-set is light loading. The load levels are set to customer specifications at the Avtron manufacturing facility for fast and precise installation.

How to choose load bank controls?

Check out this simple infographic that explains the difference between SIGMA controls and what load tests they’re optimized for.

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