ALTERNATING RELAYS

Alternating Relays equalize run times to increase equipment life and provide additional capacity. The alternating action is typically initiated by a control switch such as a float switch or pressure switch. Each time the initiating switch is opened, turning off a load, the alternating relay will change state, thus alternating the multiple loads.

Control The Run Time Of Redundant Loads

Alternating relays are used in redundant load applications to equalize run times. These relays can also be used to run multiple loads simultaneously when additional capacity is needed. Duplex Controllers are used for S.O.S.O. operation, with three switch input and alternation of which pump is turned on first. If you need help picking the right relay, contact us.

DUPLEX CONTROL, PLUG-IN

ARP Series Relays ensure that multiple loads get equal run time by alternating between two loads. In a typical application, an idle standby unit is available in case the first unit fails. Alternating relays prevent deterioration of the idle unit by equalizing run time

S.O.S.O. OPERATION, PLUG-IN

ARP Duplex Series Relays combines functions of alternating relays, control relays & auxiliary contacts in one unit. The device offers sequence on – simultaneous off (S.O.S.O.) Operation with three float switch inputs. 

DUPLEX CONTROL, FLANGE

ARF Series Relays ensure that multiple loads get equal run time by alternating between two loads. The flange mounted enclosure is used for inner-door mounting. A back-mounted socket is included with the relay.

TRIPLEX CONTROL, PLUG-IN

ATP Series Relays control up to three loads with three switch input:  LEAD, LAG and LAG2. An optional top-mounted switch allows use as a Duplex relay until system expansion requires an additional third load. 

Enclosure Style:

Function:

Output:

Control Voltage:

Standard Modifications:

Need it custom?

Need a custom engineered product? We offer engineering assistance and quick turnarounds on prototypes.

FILTER BY MODEL NUMBER:

SORT BY:

ARP Duplex

Function: 

Duplex

Control Voltage

24V AC/DC

Output:

Duplex SPDT w/ Selector Switch

Enclosure Style:

Plug-in

Standard Modifications:

Switch to select normal alternation or lock loads 1 or 2

$130.00

ARP Duplex

Function: 

Duplex

Control Voltage

24V AC/DC

Output:

Duplex SPDT

Enclosure Style:

Plug-in

Standard Modifications:

None

$122.16

ARP Duplex

Function: 

Duplex

Control Voltage

24V AC/DC

Output:

Duplex DPDT Cross-Wired w/ Selector Switch (Control Voltage pins 5 and 6)

Enclosure Style:

Plug-in

Standard Modifications:

Switch to select normal alternation or lock loads 1 or 2

$133.72

ARP Duplex

Function: 

Duplex

Control Voltage

24V AC/DC

Output:

Duplex DPDT Cross-Wired (Control Voltage pins 3 and 6)

Enclosure Style:

Plug-in

Standard Modifications:

None

$126.21

ARP Duplex

Function: 

Duplex

Control Voltage

24V AC/DC

Output:

Duplex DPDT Cross-Wired (Control Voltage pins 5 and 6)

Enclosure Style:

Plug-in

Standard Modifications:

None

$126.21

ARP Duplex

Function: 

Duplex

Control Voltage

24V AC/DC

Output:

Duplex DPDT Cross-Wired w/ Selector switch; Square Socket (Control Voltage pins 3 and 7)

Enclosure Style:

12 Pin Square

Standard Modifications:

Switch to select normal alternation or lock loads 1 or 2

$172.88

ARP Duplex

Function: 

Duplex

Control Voltage

24V AC/DC

Output:

Duplex DPDT Cross-Wired; Square Socket (Control Voltage pins 3 and 7)

Enclosure Style:

12 Pin Square

Standard Modifications:

None

$165.19

ARP Duplex

Function: 

Duplex

Control Voltage

24V AC/DC

Output:

Duplex DPDT Cross-Wired w/ Selector Switch (Control Voltage pins 3 and 6)

Enclosure Style:

Plug-in

Standard Modifications:

Switch to select normal alternation or lock loads 1 or 2

$133.72

ARP Duplex

Function: 

Duplex

Control Voltage

24V AC/DC

Output:

Duplex DPDT w/ Selector Switch

Enclosure Style:

Plug-in

Standard Modifications:

Switch to select normal alternation or lock loads 1 or 2

$133.72

ARP Duplex

Function: 

Duplex

Control Voltage

12V AC/DC

Output:

Duplex SPDT

Enclosure Style:

Plug-in

Standard Modifications:

None

$122.16

ARP Duplex

Function: 

Duplex

Control Voltage

12V AC/DC

Output:

Duplex DPDT Cross-Wired w/ Selector Switch (Control Voltage pins 5 and 6)

Enclosure Style:

Plug-in

Standard Modifications:

Switch to select normal alternation or lock loads 1 or 2

$133.72

ARP Duplex

Function: 

Duplex

Control Voltage

12V AC/DC

Output:

Duplex DPDT Cross-Wired (Control Voltage pins 5 and 6)

Enclosure Style:

Plug-in

Standard Modifications:

None

$126.21

Frequently Asked Questions About Alternating Relays

A Macromatic ARP Series Duplex Controller combines the function of an alternating relay, control relay and auxiliary contacts in one unit to provide Sequence On – Simultaneous OFF (S.O.S.O.) functionality. For 120V applications see ARP120A8R and for 24V applications use ARP024A8R.

Macromatic relays specify the power consumed by the device as “burden” in units of VA. Look for the burden specification in the catalog page for the specific device you have. The unit of VA(volt-amps) is essentially the same as Watts(power), current draw can be calculated in Amps by taking the VA specification and dividing by the voltage control voltage you are using to power the device.

Alternating Relay Downloads

Alternating Relays

Alternating Relays Competitive Comparison

ARF Series Alternating Relays Brochure

Knowledge Base Articles

Technical reports to answer your questions

Rapid Cycling of Control Switch Damages Large Pumps or Compressor Motors

Issue: How do I prevent a Bouncing Control Switch Due to Splashing Water from Rapidly Energizing One Load and Then the Other?   Solution/Resolution:  In Figure A, a single Control Switch could be susceptible to splashing water which would cause rapid opening & closing of the Control Switch.  Each time this

Using a 120V Alternating Relay with 208V Loads

Issue: Can I use an Alternating Relay with one input voltage value to control multiple loads at a different voltage? Solution/Resolution: Normally, a 120V Alternating Relay is used with 120V loads. However, there is a way to have certain versions control 208V loads.  To use a 120V SPDT ARP120A6 or ARP120A6R SPDT Alternating

Using DPDT Cross-Wired Alternating Relays with HIGH-LOW Float Switches

Issue: I have two float switches and two pumps in my application: a HIGH float switch to pump the water down and prevent an overflow of the tank, and a LOW float switch to turn the pump off and prevent the tank from being emptied burning out the pump. I bought

Typical Applications for Alternating Relays

Issue: How do I make connections to my Alternating Relay? Solution/Resolution: Macromatic offers several versions of Duplex Alternating Relays.  The following examples are typically the way connections are made to the relays.  The loads could be pumps, compressors, or air conditioning/refrigeration units:  SPDT (FIGURE A) & DPDT (FIGURE B) In the

Need Answers? Look Here.

NEED A CUSTOM ENGINEERED PRODUCT

We offer engineering assistance for you unique applications, quick turnarounds on prototypes, and the best technical support in the industry

Custom engineered product

LOCATE A DISTRIBUTOR

If you have a need for a small quantity, our Authorized Distributors have many of our products in stock, ready for immediate shipment.  They can answer any questions you may have.