Multi-Input Interface Logic
The 901-E Series Interface Logic provides a DC volt pulse width modulated signal to control the 905 Series Power Switches. The 905-M (master) includes a 901-E. The 905-S (slave) can either be driven by a 905-M or by a 901-E Interface Logic, which converts the slave to a master. The 901-E Series Interface Logic is available in two configurations. The 901-E(VmA) series accepts 0-10VDC and 4-20mA. The 901-E Series accepts 0-10VDC, 4-20mA, and a 0-135 ohm resistance. The input signal determines the percentage of time that the power switch is on and therefore the power delivered through the switch. The input signal can be derived from a thermostat, flow sensor, pressure sensor, or energy management system.
This interface is required when an analog input is being provided that requires the entire load to modulate from 0 to 100%. When a 904 Series sequencer is used to provide incremental stages combined with a proportional (modulated) SCR stage, this Interface is not required since the 904 sequencer includes its own interface circuitry and provides a PWM signal directly to the 905-S power switch.
- Multiple selectable inputs
- Field adjustable zero and span for all inputs
- Controls up to 8 power switches from one board
- Low voltage control, requires 24V AC power