gefran WATTCOR W312 Installation And Operation Manual

GENERAL PRESENTATION
The "WATTCOR W312" thyristor power controllers are designed to control:
- standard resistive loads with a low temperature coefficient
- short-wave infrared heaters
- inductive loads, transformer primaries
They can be used in the following cases:
• Single-phase: connection of the load and the unit between 2 phases or between one phase and Neutral.
• Three-phase: use of three W312, open delta or star with neutral connected.
This model is designed on the basis of a common architecture, whose dimensions are defined by the eight different cur-
rent load specifications for an ambient temperature of 50°C.
The power circuit has been designed to operate under a wide range of voltage. The working voltage can vary from a min-
imum of 24Vac to a maximum of 660Vac (Max. range 20....725Vac).
The phase angle firing device ensures accurate control of the power and fast switching.
A logic input can be used to inhibit the power output, where necessary, not withstanding the presence of the command
signal.
The LED indicators on the front indicate:
• the presence of the electronics auxiliary supply voltage;
• the conduction status of the unit.
The operating principle is phase angle firing:
The load power control is performed by slicing the individual half-waves.
The conduction angle varies in proportion to the analog control signal so that power can be adjusted from 0 to 100%.
The voltage control signal (0...5V or 0...10V) or current control signal (0/4...20mA) is normally supplied by a temperature
controller or directly from a potentiometer (manual control). A soft start function is also available.
In this case the conduction angle varies from zero up to the value corresponding to the control input in a set time.
This function is indispensable with resistive loads having low resistance when cold (tungsten, molybdenum dislicide, kan-
thal super).
A voltage of 5 Vdc is available to supply an external potentiometer for the manual control of the instrument.
Phase angle control when
analog input = 50%
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20msec
85383C_MHW_W312_0709_ENG
WATTCOR W312
POWER CONTROLLERS WITH PHASE ANGLE FIRING
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INSTALLATION AND
OPERATION MANUAL
code 85383C / Edition 04 - 07/09
Soft-Start
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RMS
Softstart time
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1