isolation transformer

The Contractor shall install and use isolation transformers. The rated output of the transformer should be consistent with the maximum rated full load value for continuous operation specified in the drawings. This isolation transformer is a NEMA ST20 compliant general purpose double shield dry type isolation transformer, factory assembled, 200% rated neutral. Each phase of the transformer has a three-wire DELTA connected input winding and a four-wire WYE connected 208Y/120 VAC output winding. The characteristics of the isolation transformer are as follows:

K factor: 20

Winding:

Copper wire: rated value as required by drawing

Harmonic Distortion: Less than 1%

Efficiency: Above 97%

Isolation System: 20°C, and 150°C Winding Temperature Rise

Impedance: 3% to 4.5% at rated load

Basic pulse level: 10kV

Common Mode: -120db, 10Hz to l Mhz

Standard mode: 20db/decade

Ventilation equipment: Convection cooling

Taps: Compensation taps are provided on the main windings to allow for magnetic field changes from high or low voltage sources as follows:

FCAN = Full Capacity Above Normal (Tap): 1%, 1.5%, 2%, 2.5%, 3%, 5%

FCBN = full capacity below normal (tap): 1%, 1.5%, 2%, 2.5%, 3%, 5.0%, 7.5%, 10%

Temperature Sensors: Two temperature sensor wraps are each wrapped around the coil "hot spots". The switch is a normally open contact type switch. The switches are connected through a junction box and installed inside the cabinet. At 180°C, the first contact closes, and at the same time, a light-emitting diode is activated to illuminate and activate an alarm at the status panel to alert. At 195 °C, the second contact closes, tripping the main input circuit breaker. A light-emitting diode activates the lighting and an alarm on the status instrument panel begins to alert.