The SIGMA E-Series air conditioner, 12VDC & 24VDC, has been designed and developed for cost effective medium duty off road applications. Refined to suit the application of vibration, dust and high ambient to suit rubber tyred quarry, construction and mobile fleets, where all components are readily available and provide reliable service and ease of service.


Driver’s comfort is an important aspect to ensure the safe operation of rolling stock networks globally. Sigma’s locomotive driver’s cab air conditioning systems have been designed to operate in some of the harshest conditions around the world, where outside temperatures reach as high as 50°C (122°F).

This reliable air conditioning system is the result of Sigma’s striving for engineering excellence, over 65 years of experience in locomotive air conditioning industry and continuous development. It operates with environmentally friendly R134a refrigerant, comprisses DC Operating Fan Motors (evaporator, fresh air and condenser fan motors) operate directly on 72VDC supply input, includes a PLC controller and is able to run in service at extreme high ambient temperatures of 60°C (140°F).


The SIGMA M-Series heavy duty mains powered air conditioners are designed to provide controlled space conditions for crane operators cabins, control rooms, switch rooms and other applications where heavy shock loads, vibration and dust laden corrosive environments are experienced and ambient temperatures approach the extreme.