SPA
4
The Interface Solution Experts
Site-Programmable RTD &
Thermocouple Limit Alarm Trips
SPA Temperature Inputs
This is the users’ manual for the Temperature Input
model of the Moore Industries’ Site-Programmable
Process Alarms (SPA). The SPA monitors a
process variable and provides up to four, fully user
configurable, contact closure outputs whenever the
input falls outside a user-set, high or low trip point.
SPAs are typically used to activate a warning light, bell,
or buzzer; or to initiate a system shutdown, thus acting
as a simple, but highly reliable and effective means of
safe-guarding a process.
Programmable Inputs
The Programmable RTD & Thermocouple unit, or SPA
TPRG (for Temperature input Programmable) handles
inputs from RTDs, thermocouples, direct resistance
and millivolt sources.
Programmable Outputs
The SPA TPRG can be equipped with an analog
output option to provide either a 1-5V or 4-20mA
output (-AO), or zero-based, 0-5V or 0-20mA, output
(-AOZ). Both AO and AOZ equipped units are set by
the user to provide either current (switchable between
source or sink modes), or voltage.
The source/sink setting for the optional analog output
is controlled by DIP switches that are located behind
an easy-to-remove access panel inside the unit’s
housing.
Programmable Display
With the RTD and Thermocouple Input SPA, the
display is directly proportional to the input. The user
can program the unit’s display to show either °C or °F
– with a simple push of a button.
Programmable Alarms
The SPA can be ordered with 1, 2, 3, or 4 contact
closure alarms. Each alarm can be individually
programmed for a different trip point, deadband, delay,
high or low alarming, latching or non-latching, and
failsafe or non-failsafe operation.
The SPA also provides two ways to set the alarm
trip point. If an input source is either unavailable or
inconvenient, the unit’s front panel push buttons and
integral liquid crystal display (LCD) can be used to
enter the desired trip point.
When a source is available, the SPA can capture
trip points by setting the input to the desired trip and
pressing the appropriate button.
Failsafe or Non-failsafe alarm functioning is controlled
by DIP switches that are located behind an easy-to-
remove access panel inside the unit’s housing.
Total Sensor Diagnostics
The standard SPA TPRG features a patented input
circuit that eliminates much of the time consuming
trial-and-error work of troubleshooting sensor
networks. Total Sensor Diagnostics (TSD) is the SPA’s
continuous monitoring of the status of both the input
sensor and its wiring.
If a wire breaks, or if the sensor fails, a front panel
LED corresponding to the input changes color to flag
the problem, and the LCD displays a message telling
exactly where the failure has occurred.
In multiple RTD, or ohms input applications, messages
on the front panel indicate which sensor has failed or
which wire has broken. The unit distinguishes between
failures on one of the wires or the sensor itself, or
between one wire and another.
The SPA also allows the user to program the unit
alarms to change state (trip) in the event of an input
(sensor) failure. When equipped with one of the
analog output options, the user can also program the
unit’s current or voltage output to drive upscale or
downscale in the event of a failure.
An optional single alarm failure configuration (-SF3)
freezes all but one of the alarms upon a sensor failure,
tripping only relay #3.
Universal Mounting
The SPA is housed in a “universal” DIN case that can
be mounted on both 32mm G-type (EN50035) and
35mm Top-Hat (EN50022) DIN-rail. The Installation
section of this manual gives the dimensions of the
housings for the various SPA configurations.
