Calibration - Acromag 461A Series User Manual

Series 461A User's Manual
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3. Output Contacts: Wire contacts as shown in the connection
Drawing 4501-542. See label on unit for contact rating. Refer
to Drawing 4501-544 for suggestions on relay contact
protection.
Electromechanical Relay Contact Protection: To maximize
relay life with inductive loads, external protection is required. For
DC inductive loads, place a diode across the load (1N4006 or
equivalent) with cathode to (+) and anode to (-), see Drawing
4501-544. For AC inductive loads, place a MOV across the
load, see Drawing 4501-544.
IMPORTANT: Noise and/or jitter on the input signal has the
effect of reducing (narrowing) the instrument's deadband and
may produce contact chatter. The long term effect of this will
reduce the life of mechanical relays contacts. To reduce this
undesired effect, increase the deadband setting.
4. V/mA Input: Connect input per connection Drawing 4501-535.
Observe proper polarity. If the input is a 4 to 20mA signal, a
jumper must be installed between the Input (+) and Input (L)
terminals. Current is delivered to the Input (+) terminal and
returned at the Input (-) terminal. Voltage signals are connected
to the Input (+) and (-) terminals.
NOTE: The Input, Output, and Power circuits are isolated from
each other, allowing the input circuit to operate with common
mode voltages up to 250V AC, or 354V DC, off ground, on a
continuous basis.
5. AC Current Input: The AC Current Sensor is isolated and can
be used in AC circuits up to 250V AC, 50 or 60 Hz. It is
designed to be mounted at the source of the AC current to be
measured. The sensor outputs a low-level DC milliampere
signal, allowing the transmitter to be mounted remote from the
AC signal using small gauge wire. The sensor's output
(Red/Black) wires can be shorted, open-circuited, or removed
from the transmitter's input terminals, without hazard to
personnel or to the AC Current Sensor.
AC Current Sensor: Per the Input Range chart in the
Specifications Section, loop the required number of turns
through the toroid for the full-scale range that you need in your
application. Use the cable tie provided to mechanically secure
the sensor. Refer to Drawing 4501-546.
DANGER: If the AC Current Sensor is used with an AC
Current Transformer (C.T.), disconnect power to the C.T., or
short the output of the C.T., before removing the wire going
through the AC Current Sensor. If this is not done, an open
circuited C.T. will generate high voltages (hazardous) and
possible C.T. damage.
The sensor output wires should be connected to the extension
cable (wires) using wire nuts, or equivalent. Sensor output
wires are color coded RED (+) and BLACK (-), proper polarity
must be observed.

CALIBRATION:

This section provides information for unit configuration and
calibration. If the unit was factory calibrated, jumpers have been
placed in their proper positions and verification of the calibration can
be made per the Adjustment Procedure. If the calibration of the unit
is to be changed, first go to the "Shunt Block Configuration
Procedure", before going to the Alarm Adjustment Procedure."
Alarm - Shunt Block Configuration Procedure:
The Series 461A Alarm is quite universal in that it can be
configured as a HIGH (HI) or LOW (LO) alarm and can operate in
the Failsafe or Non-Failsafe mode. Before the adjustment procedure
can proceed, the jumpers must be configured for the requirements
of the application (refer to Drawing 4501-545 for details). To gain
access to the configuration jumpers, first remove the alarm from the
installation. Second, remove the circuit boards from the plastic
enclosure as described in the following Disassembly Procedure
(refer to Drawing 4501-545). Third, configure the jumpers (shunt
blocks) as described in the Jumper Configuration procedure below.
Fourth, install the circuit board into the plastic enclosure as
described in the Assembly Procedure.
Disassembly Procedure for the 461A Plastic Housing:
The plastic housing has no screws, it "snaps" together. A flat-
head screwdriver (Acromag 5021-216 or equivalent) is needed to pry
the housing apart as described in the following steps.
CAUTION: Do not push the screwdriver blade into the housing
more than approximately 0.1 inches while prying it apart. Handling
of the printed circuit board should only be done at a static-free
workstation, otherwise, damage to the electronics could result.
1. To begin disassembly (refer to Drawing 4501-545) place the
screwdriver at point A (left side of the alarm). While pressing
the blade into the seam, use a twisting motion to separate the
sides slightly. Repeat this operation at point B.
2. Now that the two pieces have been partially separated, use the
screwdriver blade to work the left side of the package loose by
working around the alarm and carefully prying the sides further
apart. Repeat this action until it is easy to remove the left side
from the plastic pins holding the pieces together.
3. Repeat this operation for the right side starting at points C & D.
CAUTION: If the two PC boards become separated while taking the
package apart, re-align the boards making sure that both
interconnection headers are aligned with their mating sockets and
carefully push the boards back together.
Jumper Configuration (Shunt Blocks):
Shunt blocks are provided to accommodate in-field configuration
changes. In case of misplacement, additional shunt blocks may be
ordered from the factory. When ordering additional shunt blocks,
refer to Acromag Part Number 1004-332.
1. HIGH (HI) or LOW (LO) Alarm action: Refer to table on
Drawing 4501-545 for proper jumper (shunt) position.
2. Failsafe or Non-Failsafe Mode: Refer to table on Drawing
4501-545 for proper jumper (shunt) position.
3. IMPORTANT: Mark the Alarm's Configuration on the calibration
label located on the enclosure. Example: CH1, HI, FS or CH2,
LO, NFS.
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Single/Dual Alarm