The tables and diagrams on the following pages illustrate the module types (6A and so on) and contact arrangements that
can be ordered for the relay. Since an entire row is used for a single contact output, the name is assigned using the module
slot position and row number. However, since there are two contact inputs per row, these names are assigned by module
slot position, row number, and column position.
Some form-A / solid-state relay outputs include circuits to monitor the DC voltage across the output contact when it is
open, and the DC current through the output contact when it is closed. Each of the monitors contains a level detector
whose output is set to logic "On = 1" when the current in the circuit is above the threshold setting. The voltage monitor is
set to "On = 1" when there is a voltage across open contact (the detector allows a current of about 1 to 2.5 mA), and the
current monitor is set to "On = 1" when the current flowing through the closed contact exceeds about 80 to 100 mA. The
voltage monitor is intended to check the health of the overall trip circuit, and the current monitor can be used to seal-in
the output contact until an external contact has interrupted current flow. If enabled, the current monitoring can be used as
a seal-in signal to ensure that the form-A contact does not attempt to break the energized inductive coil circuit and weld
the output contacts.
Block diagrams are shown as follows for form-A and solid-state relay outputs with optional voltage monitor, optional
current monitor, and with no monitoring. The actual values shown for contact output 1 are the same for all contact
outputs. Form-A contact output with or without a current or voltage monitoring option is not polarity sensitive. The polarity
shown in the figure is required for solid-state contact output connection.
Figure 3-11: Form-A and solid-state contact outputs with voltage and current monitoring
The operation of voltage and current monitors is reflected with the corresponding FlexLogic operands
CONT OP #
monitor is breaker trip circuit integrity monitoring; a typical application of the current monitor is seal-in of the control
See the Digital Elements section of chapter 5 for an example of how form-A and solid-state relay contacts can be applied
for breaker trip circuit integrity monitoring.
ION) that can be used in protection, control, and alarm logic. The typical application of the voltage
Consider relay contacts unsafe to touch when the unit is energized. Death or serious injury can
result from touching live relay contacts.
CHAPTER 3: INSTALLATION
(CONT OP #
C30 CONTROLLER SYSTEM – INSTRUCTION MANUAL