Data Flow Systems TCU800, Installation And Operation Manual

Page: 25 / 162

15
U n i t O v e r v i e w
Single/Three Phase: Single or three-phase voltage systems can be monitored with ranges of nominal 240 and 480
VAC. The 480 VAC systems require external resistors installed on each phase.
Fault Detection: Fault detection is provided for loss of a phase, phase reversal, and low/high voltage conditions.
Faults will automatically stop all pumps from running to prevent damage.
External
The external phase monitor must provide a closed set of contacts that open during a phase fault. The voltage used to
monitor the set of contacts must be the same voltage used to monitor the pump run statuses.
Internal Monitoring
The TCU800 monitors several internal features to provide the user with the status of how the unit is operating. These sta-
tuses are internal temperature, AC Power Fault, DC Bias Fault, and Process Fault.
Internal Temperature
Internal temperature monitors the TCU800’s temperature.
AC Power Fault
AC Power fault is provided when no AC power is applied to the unit. This will only be available when the TCU800 is on
battery backup.
DC Bias Fault
The DC Bias fault is active when the 24VDC bias power supply drops below 20VDC.
Process Fault
The process fault is active when the control program is detected as no longer operating.
Automatic/Manual Control
When the TCU’s Hand-Off-Auto (H-O-A) switches are in the “Auto” position, the TCU provides automatic control over a
pump system. However, there are two ways to partially or completely override the TCU and manually control the system:
the H-O-A switches and telemetry interface.
H-O-A Switches
Three H-O-A switches on the TCU’s face plate are provided to manually override the TCU’s automated control.
Hand
Placing a switch in the “Hand” position overrides the TCU’s control and forces the corresponding
pump on.
Off
Placing a switch in the “Off” position overrides the TCU’s control and forces the corresponding pump
off.
Auto
The H-O-A switch for a pump must be in the “Auto” position for the TCU to provide automatic
control whether manually over telemetry or automatically via the TCU coontrol programming.
The H-O-A switches are fail-safe; they remain operational even if the TCU fails or loses power. They will continue to
function in the “Hand” and “Off” positions with the TCU in a faulted state or powered down. Motor Starter faults are reset
when the corresponding H-O-A switch is moved from the “Auto” position.