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Process
Control
Equipment for
Hazardous
Locations
7M26
UL913
INCLUDES
INTRINSICALLY
SAFE INPUTS
Integrated Duplex Controller
SOSO Operation
(Sequence-on, Simultaneous-o)
SPECIFICATIONS
CONTROL VOLTAGE 24 or 120 VAC ±10%, 50/60 Hz
CONTROL SWITCH Open Circuit 5 VDC
Voltage
Short Circuit 0.1mA
Voltage
POWER REQUIRED 4 VA Maximum
DUTY CYCLE Continuous
RESPONSE Power Up 3 SEC. ±5%
Inrush Current 5 SEC. ±5%
CONTACT (3) SPST-N.O. 10 Amp Resistive, 1/4 hp, 278 VA
RATING Inductive @ 120 VAC
LED INDICATORS Designation Color State Condition
Level/Alarm Red ON cs5 Closed
Lag Green ON cs4 Closed
Lead Green ON cs3 Closed
ALTERNATING RELAYS & CONTROLLERS ARM Series
LIFE EXPECTANCY Mechanical 20 Million Operations
TEMPERATURE Operate -4° to 131°F (-20° to +55°C)
RATING Storage -40° to 185°F (-40° to +85°C)
TERMINATIONS (12) #8-32 Screw Terminals
WEIGHT 16 oz.
Off Green ON cs2 Closed
Aux. Off Green ON cs1 Aux./cs2
Load 1 Green ON Load ON
Load 2 Green ON Load ON
Ctrl. Switch Red ON Failure
Electrical 75,000 @ Rated Load
Closed
Open/Closed
The ARM Series Alternating Relay is a microprocessor-based
controller designed for use in dual load installations to assure
equal run time on each load. LED indicators show the status of
the unit’s five intrinsically safe control switch inputs, one alarm,
and two load outputs. H-O-A switches, a lead select switch, and a
test/clear button are provided for manual control. The ARM Series
reduces the number of components required for this application
by combining many functions into one unit.
TWO PUMP SEQUENCING: Evenly distributes run time by automatically alternating lead and lag load designations when the off
control switch input opens.
UL913 INTRINSICALLY SAFE: Control switch inputs are low voltage/
low current and are electronically isolated from the control voltage
and load alarm contacts.
H-O-A Switches: Hand-Off-Automatic switches allow for manual
operation.
LEAD SELECT SWITCH: Disables the automatic sequencing function
and allows loads to be locked into the 2-1 or 1-2 sequence.
CONTROL SWITCH FAULT DETECTION: Unit detects open and
shorted control switch failures.
TEST/CLEAR SWITCH: Verifies function and resets the control
switch fault detection algorithm.
ALARM OUTPUT: Alarm contacts close when a control switch
fails or the system’s capacity is exceeded.
INRUSH CURRENT DELAY: Reduces line sags by preventing
both loads from energizing simultaneously.
VERSATILE MOUNTING: Two (2) mounting configurations are
available. The standard surface mount has top access to controls
and indicators and is intended for back panel mounting. The panel
mount option is intended for front panel or door cutout access to
controls and indicators.
SPECIAL CONTROLS: ARM-2003 and ARM-2010–Standard
operation without the H-O-A switches ARM-2011–Standard
operation without the Control Switch Failure feature.
ORDERING INFORMATION
MODEL CONTROL
NUMBER VOLTAGE MOUNTING COMMENTS
ARM-XXX-AFE* 24 or 120 VAC Surface Standard
ARM-XXX-AFEP* 24 or 120 VAC Panel Standard
ARM-2003 120 VAC Surface Special: w/o
H-O-A switches
ARM-2010 120 VAC Panel Special: w/o
H-O-A switches
ARM-2011 120 VAC Surface Special: w/o
Control switch
failure feature
*Replace XXX with desire control voltage (24, 120)
192
The ARM Series is UL Listed under UL File Number E151578.
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*Panel Mount Cutout
OPERATIONDIMENSIONS (INCHES)
FOUR CONTROL SWITCHING: Do not remove factory-installed jumper
between terminals 2 and 3. The control switches connected to terminals 3 through 6 are labeled OFF (CS2), LEAD (CS3), LAG (CS4)
and ALARM (CS5). Under normal operation the lead load energizes
when the off and lead control switches close in order. The lag load
energizes when the lag closes and the alarm load energizes when
the alarm switch closes. When all four switches reopen in the proper
order all outputs are de-energized and the lead/lag output designations reverse.
FIVE CONTROL SWITCHING: Remove factory installed jumper
between terminals 2 and 3. After the jumper has been removed, the
additional control switch is connected to terminal 2. The extra switch
functions as an AUXILIARY OFF (CS1) switch. It is used to prevent
loads from running continuously if the primary OFF (CS2) switch
fails to open properly.
FAULT DETECTION ALGORITHM: If any of the control switches open
or close out of order, the alarm output energizes and a fault detection algorithm is used to identify the faulty switch. The faulty switch
is then ignored and the OFF, LEAD, and LAG control switch designations are altered to maintain safe operation.
*Greenlee punch #60071 or equivalent
WIRING
CONTROL DRAWING 190
1. To maintain intrinsic safety, connect the Controller’s Earth Ground Terminal 8 to the earth ground of the AC Power Supply feeder.
The resistance between the Controller’s Earth Ground Terminal and Earth Ground shall be less than 1 ohm.
2. Maximum distance between Controller and switch contact is 1000 feet.
3. All intrinsically safe wiring shall be separated from non-intrinsically safe wiring. Refer to article 504 of the National Electrical Code
ANSI/NFPA 70 on procedures for intrinsically safe wiring.
4. Switch contact shall be any non-energy storing or generating mechanical switch type device containing no capacitance or inductance.
5. Connections to terminals 5, 6, 9, 10, 11, and 12 are optional. If the Aux. Off switch is omitted, terminals 2 & 3 must be jumpered.
ALTERNATING RELAYS & CONTROLLERS ARM Series
193