Specifications

13
Series RMB Hot Runner Controller Instruction Manual
5.3 Ground Fault in
Controller Output Wiring
The RMB controller detects ground faults
in the controller output wiring by
monitoring the current to ground. If the
current to ground is 55 mA or higher, the
controller attempts to perform a normal
soft start if the process value is less than
or equal to 200°F (93°C). The standard
CompuStep soft start described in 1.2 is
executed. In this special case, the soft
start will be executed up to three times. If
the ground fault is still detected, the
controller considers this a “hard” ground
fault.
If a ground fault is detected when the
process value is greater than 200°F
(93°C), the controller considers it a “hard”
ground fault immediately.
When a hard ground fault is detected, the
controller:
• interrupts the signal to its own output,
in effect “turning off” the output, and
• an error message
9FI is displayed on
the lower line, and
• the red ALARM LED lights (all other
LEDs off).
Following the interrupt in response to a
“hard” ground fault, the controller’s output
remains off until you cycle power to the
controller.
5.4 Loop Break in Sensor
Wiring
If the input value does not change at least
1% of supported sensor span (9.67°F or
5.37°C) within 999 seconds while the
controller output is on, and a “bad heater”
error has not been detected (see 5.6),
then:
• the controller output goes to 0%, and
• the red ALARM LED lights (all
other LEDs off), and
• the message LPbr is displayed on the
lower line.
The controller remains in this alarm and
output off state until you cycle power to
the controller.
5.5 Open Thermocouple
If the controller detects an open sensor:
• the red ALARM LED lights (all other
LEDs off), and
• the upper display alternates tC and
oPn (open sensor), and
• the appropriate output action is taken,
depending on control mode:
• if the controller is in normal (auto)
mode, the output goes to 0% for
approximately one second, and then
the controller uses a calculated out
put value, based on stored output
values that have successfully
maintained the current setpoint for
your process in the past
• if the controller is in manual mode,
the output remains at the percent in
use when the open sensor was
detected
The controller remains in this alarm and
failsafe state until the condition clears or
you cycle power to the controller.
5.6 Reversed Thermocouple
Leads
If the controller detects a reversed sensor:
• the controller output goes to 0%, and
• the red ALARM LED lights (all other
LEDs off), and
• the upper display alternates tC and
rEu (reversed sensor).
The controller remains in this alarm and
output off state until the condition clears or
you cycle power to the controller.