Ferro-resonant constant voltage transformers or CVTs are recognized as one of the most effective methods providing voltage regulation and high-frequency switching noise isolation for sensitive industrial control devices. A more unique benefit is the ability to protect connected equipment from sags or dips well beyond the steady state voltage regulation specification of the CVT. In fact, when properly sized, these voltage-regulating transformers can provide a nominal output voltage – even if the input voltage momentarily sags to 50 percent of nominal.

The superior voltage regulating capability of PQSI’s premium line of CVTs enables the system output voltage to stay very close to nominal during all types of power quality variations, thereby keeping sensitive process control equipment up and running, and eliminating unnecessary facility downtime.

PQSI Inc. has performed extensive characterization of constant voltage transformers and has selected a product line that provides premium sag mitigation for protected loads. PQSI CVTs are frequently designed with unique input/output voltage configurations that are not normally available from other manufacturers. In particular, select PQSI models allow for unobtrusive installation on the 480Vac side of existing control power transformers or on the 120Vac secondary side. All CVT models are designed to meet stringent PQSI performance criteria and to meet the needs of process and facility engineers who require the benefits of sag regulation, but cannot find the necessary output voltage configuration to meet their process control requirements. PQSI's unique input/output voltage configurations allow the user to still get all of the stepped down output voltages available from their existing control power transformer while gaining the benefit of sag protection in an extremely cost effective manner. PQSI offers a complete line of CVT's in a variety of input and output voltage configurations from 500VA to 5000VA.