Alarm devices are turned ON/OFF via relay contacts that are part of the controller, which set the threshold limits that activate the relays. A typical alarm sequence is to activate a yellow light for Low alarm, and then to activate a red light and audible signal for a High alarm. It is often desirable to silence the audible alarm while investigating the source of alarm. However, a simple ON/OFF switch which disables the audible alarm can be dangerous as the alarm condition can remain while there is nothing to signal it. Therefore, it is important to consider an alarm processor to ensure proper safety.
Model 9927 Alarm Processor: Accepts eight channels of alarm contacts; three alarms for Low, High and Malfunction conditions per channel.
There are three summary relays, one for each alarm level, an audible buzzer and an Acknowledge push button switch. It functions as a typical annunciator sequence per Instrument Society of America Sequence A, automatic reset, as described below:
Sequence State
Ack Switch
Visual Display
Audible Alarm
Normal
None
OFF
OFF
Alarm
None
Flashing
Audible
Acknowledge
Acknowledge
On
Silent
Normal
None
Off
Silent
The 9927 provides a locking key switch that permits calibration and testing without causing an audible alarm. Appropriate input terminals are provided to permit a connection to a battery power backup source.
9927 Specifications
Dimensions:
19.0" W x 5-1/4" H x 9.0" D
Weight:
Power:
110/220 VAC 50/60 Hz, 15W
Input Channels:
8
Alarm Input Per Channels:
3
Summary Relays:
3 (Warn, Alarm, Malfunction)
Relay Operating Mode:
Failsafe-loss of power or input connection will de-energize relay to the alarm state condition
Relay Contacts:
2C (DPDT) for each, 2A resistive at 22V AC
Relay Disable:
Keyswitch (for calibration, etc.). LED flashes to warn of disable condition
Audible Alarm:
Pulsating audible tone for any Warn, Alarm, or Malfunction until the Acknowledge switch is pressed
Acknowledge:
Operator push-button switch will acknowledge all alarm conditions, restoring relays to non-alarm state, silencing the audible alarm, and changing the status LED alarm indicator from flash to steady until alarm condition ceases
PB100 Time Delay Relay: Programmable, multifunction digital time delay relay
PB100 Specifications • 10 programmable timing functions plus 2 counting functions
• 0.1 second to 9990 hour programmable timing range
• 1 to 99,900 counting range
• Universal input (24-240V 50/60 Hz, AC or DC)
• 10A, 240VAC or 30 VDC, DPDT electrochemical relay output
• LCD digital display
• Programming thumb wheel switches
Model 9928-BH Beacon/Horn Wall-mount enclosure with strobe beacon and 98 dB horn for indoor or outdoor applications
9928 Specifications
Enclosure:
NEMA 12 Weatherproof for indoor or outdoor
Dimensions:
16" H x 9-1/4" W x 6-1/4" D
Weight:
Approximately 10 pounds
Power:
110/220 VAC 50/60 Hz, or 24 VDC optional
Alarm Outputs:
Visual:
1 blue strobe beacon is standard. Red or amber beacons available
Audible:
78 to 101 dB (DC vibrating) horn
Manufacturer:
Edwards Model 875-G1
Options:
Silence Switch:
On/Off switch to silence the horn as needed
Timer Relay:
The timer relay can be configured at the factory to accomplish several functions. The most typical usage is to automatically silence the built-in horn for a specified period. IST pre-programs the time interval during manufacturing via a combination of toggle switches and timer thumb wheel switches.
Model 9938-2LH Beacon/Horn: Wall-mount enclosure with strobe beacon and 98 dB horn for indoor or outdoor applications
9938-2LH Specifications
Enclosure:
NEMA 12 Weatherproof for indoor or outdoor
Dimensions:
14" H x 9-1/4" W x 6-1/4" D
Weight:
8 pounds
Power:
110/220 VAC 50/60 Hz
Alarm Outputs:
Visual:
One red and one blue light
Audible:
78 to 101 dB (DC vibrating) horn
Manufacturer:
Edwards Model 875-G1
Options:
Silence Switch:
On/Off switch to silence the horn as needed
Timer Relay:
The timer relay can be configured at the factory to accomplish several functions. The most typical usage is to automatically silence the built-in horn for a specified period. IST pre-programs the time interval during manufacturing via a combination of toggle switches and timer thumb wheel switches
Model 9929-LH Rack-Mount Alarm System: Has the capabilities and options of Model 9928 plus three DPDT relays
5-1/4" x 19" (standard EIA dimensions) device designed for mounting into rack cabinet or panel. It has all of capabilities and options of the Model 9928. In addition, it has three DPDT relays (one for each type of alarm condition), rated 10 amps, resistive. These relays may be used to activate ventilation fans, sirens, or other equipment.
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