Cecilware GB4M-5.5-LD-U - Manual (Page 9)

Model L690A (Rev. B) Dual Probe Liquid Level Controller
Overview - The L690A is a Dual Probe Liquid Level Controller designed to maintain a specific level
of water in the tank. This device utilizes two level probes for increased reliability. Independent
maximum fill timers are incorporated in the controller for overflow protection.
Operation - When a fill problem occurs, the Dual Probe Liquid Level Controller turns OFF power to
the fill valves and remains OFF until the power input is reset (i.e. turn power switch off then back
on).
Low Level Probe - When the Low Level Probe detects the absence of water for two seconds, the
Controller immediately opens the Fill Valve. When the Low Level Probe detects the presence of
water the Controller immediately closes the Fill Valve.
High Level Probe - When the High Level Probe detects the absence of water the Controller
immediately turns ON and the Low Level Probe is allowed to control the Fill Valve. When the High
Level Probe detects the presence of water for 1.5 seconds the Controller turns OFF power, which
closes the Fill Valve.
Maximum Fill Timers – On the first fill, the unit will only allow 15 minutes of continuous filling if
neither of the Level Probes has detected the presence of water since power has been applied (i.e. first
fill). Once the presence of water has been detected the unit will only allow 10 minutes of continuous
filling to prevent flooding. If the duration of continuous filling exceeds the allotted time then a Fatal
Error is generated, which closes the inlet valve.
Status LED – Located on the Controller, this indicator is turned ON for one second after power is
applied to indicate a functioning unit. The indicator will blink when the High Level Probe detects
water to signify a warning. During a Fatal Error the indicator will be ON continuously.