Littelfuse-ALT-100-3-SW

Protection Relays  

Pump Controls and Liquid Level Controls  

ALT-XXX-1-SW / ALT-XXX-3-SW SERIES  

Alternating Relay  

Description  

The AL

T

–

xxx-1-SW/AL

T

–

xxx-3-SW Series are used to alternate  

between two loads and are commonly used in duplex  

pump-up and pump-down applications to balance the runtime  

of both pumps.  

The ALT relays have a built-in debounce time delay that prevents  

the relay from changing state if the float momentarily bounces,  

and they have a built-in switch to manually force a specific load  

(pump) to operate each time the input float closes. This is helpful  

when performing periodic maintenance or pump repair.  

Must use the OT08PC socket for the 8-pin models, and the OT11PC socket for the  

11-pin models, for UL Rating!  

*Note: Manufacturer’s recommended screw terminal torque for the OT Series  

Octal Sockets is 12 in.-lbs.  

Features & Benefits  

Wiring Diagram  

FEATURES  

BENEFITS  

TYPICAL WIRING DIAGRAM FOR A

L

T

–

XXX-1-SW  

Prevents rapid cycling caused by waves or splashing  

in the tank  

Debounce time delay  

Visual indication of load operation in  

duplex application  

LED indicators  

Built-in manual switch  

to force load operation  

Helpful to control load operation when performing  

periodic maintenance or pump repair  

A

L

T

–

xxx-3-SW  

offers duplexing  

Allows lag pump to energize if lead pump can’t  

handle current demand  

Accessories  

OT08PC 8-pin

 

Octal Socket  

Octal Socket for plug-in units. 8-pin surface &  

DIN rail mountable. Rated for 10A @ 600VAC.  

OT11PC 11-pin

 

Magnal Socket  

11

–

pin surface & DIN rail mountable. Rated for  

10A @ 300VAC  

TYPICAL WIRING DIAGRAM  

FOR A

L

T

–

XXX-3-SW  

Ordering Information  

LINE  

VOTAGE  

MODEL  

MOUNTING DESCRIPTION  

Single float input, two isolated  

Form C relays (DPDT), 2 LEDs  

for load indication  

11-pin  

magnal  

ALT-100-1-SW 95-120VAC  

Three float inputs (lead, lag,  

stop floats), actuating latching  

relays on lead/lag floats,  

2 LEDs for load indication  

ALT-100-3-SW 95-120VAC

 

8-pin octal  

ALT-200-3-SW 190-240VAC 8-pin

 

octal  

Three float inputs (lead, lag,  

stop floats), actuating latching  

relays on lead/lag floats,  

2 LEDs for load indication  

© 2016 Littelfuse Protection Relays & Controls  

Rev: 1-A-062716  

Protection Relays  

Pump Controls and Liquid Level Controls  

ALT-XXX-1-SW / ALT-XXX-3-SW SERIES  

Standards Passed  

Electrostatic Discharge (ESD)

 

IEC 61000-4-2, Level 3, 6kV contact, 8kV air  

Specifications  

Input Characteristics  

Supply Voltage  

Radio Frequency, Radiated  

Fast Transient Burst  

150MHz, 10V/m  

IEC 61000-4-4, Level 3, 3.5kV  

input power and controls  

ALT-100-1-SW,  

ALT-100-3-SW  

ALT-200-3-SW  

Frequency  

Functional Characteristics  

Debounce Time Delay  

ALT-100-1-SW,  

ALT-100-3-SW,  

ALT-200-3-SW  

Output Characteristics  

Output Relay (DPDT)  

Pilot Duty  

General Purpose  

General Characteristics  

Temperature Range  

Maximum Input Power  

95-120VAC  

190-240VAC  

50/60Hz  

Safety Marks  

UL (OT08PC or OT11PC  

octal socket required)  

CE  

UL508 (File #E68520)  

IEC 60947-6-2  

Dimensions  

H

44.45 mm (1.75”);

W

60.33 mm (2.375”);  

D

104.78 mm (4.125”) (with socket)  

0.65 lb. (10.4 oz., 294.84 g)  

DIN rail or surface mount (plug into OT08PC  

or OT11PC socket)  

1 second  

Weight  

Mounting Method  

5 seconds  

Sockets Available  

Model OT08PC  

Model OT11PC  

480VA @ 240VAC  

10A @ 240VAC  

UL Rating 600V  

UL Rating 300V  

-40° to 70°C (-40° to 158°F)  

5 W  

The sockets can be surface mounted or installed on DIN Rail.  

© 2016 Littelfuse Protection Relays & Controls  

Rev: 1-A-062716