
Littelfuse ALT-230-S The ALT alternating relays are used to alternate between two loads. The ALT is commonly…
Alternate Item Number: ALT230-S
UPC: 079458991352
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Contact for Pricing
Call +1 (262) 252-1600 (toll-free 877-268-3700) or email [email protected] for pricing and availability.
Overview
- 8-pin plug-in alternating relay for duplex pump applications
- Built-in debounce protection prevents false state changes from switch bounce
- ALT-S variant for single high-level float applications
- ALT-X variant allows simultaneous pump operation in dual float systems
- Optional SW switch for manual pump force-start during maintenance/testing
Specifications
Brand Name | Littelfuse |
Mounting | DIN rail or Surface mount (plug into OT08-PC socket) |
Number Of Poles | DIN rail or surface mount (plug into OT08-PC socket) |
Operating Temperature | -40 to 158 |
Operating Temperature, Maximum | 158 |
Operating Temperature, Minimum | -40 |
Pickup Voltage | 195-250 V |
Series | ALT Series |
Special Features | 5YR WARR |
Standard | UL/CSA |
Sub Brand | Symcom |
Package Dimensions (L x W x H) | 4.13 IN x 2.38 IN x 1.75 IN |
Package Dimensions (L x W x H) | 104.8 mm x 60.3 mm x 44.5 mm |

ISS-105-ISO
The ISS-105 is a “smart” five-channel intrinsically safe relay and pump controller. The ISS-105 can be configured for a wide variety of applications including alternating or non-alternating duplex, duplex separate pump stop (SPS), triplex and quadplex applications. It can be set up for pump-up or pump-down applications or can be used as a five-channel relay. The ISS-105 has a long list of features that are needed for multiple pump applications. The ISS-105 can indicate low, high and out-of-sequence alarms. If an out-of-sequence alarm occurs, the skipped pump(s) will be started as intended. The Model ISS-105 can be set up to do non-alternating control, alternating control and alternating control with one non-alternating pump. The non-alternating pump is intended for use with an emergency or jockey pump. The ISS-105 can start an emergency pump once every 50 cycles to keep it working freely. Using the built-in DIP switches, individual pumps can be disabled when taken out of service for repair or maintenance.
ALT-115-X-SW
The ALT alternating relays are used to alternate between two loads. The ALT is commonly used in duplex pumping applications to balance the runtime of both pumps. The ALT-S is used in single high-level float applications. When the float switch opens, the alternating relay changes state, forcing the other pump to run the next time the float closes. All ALT relays have a built-in debounce feature that prevents the relay from changing state if the switch or float contact bounces momentarily. The ALT-X has an internal cross-connected relay and is used in dual high-level float applications. These floats are commonly referred to as lead and lag floats. The pumps alternate as in the ALT-S version but the crossconnected relay configuration allows both pumps to run simultaneously when both the lead and lag floats are closed. These relays are also available with a built-in switch (SW option) that is used to manually force one of the pumps to run every time the float switch is closed. This is helpful when a pump has been removed for repair or for test purposes. In the case of the ALT-X-SW, the switch essentially forces one pump to be the lead pump, while still allowing the second to run when both floats are closed. Must use the OT08PC socket for UL Rating!
201-200-SP
The 201-xxx-SP is an 8-pin octal-base, plug-in voltage monitor designed to protect single-phase motors regardless of size. The 201-100-SP is used on 95-120VAC, 50/60Hz motors to prevent damage caused by low voltage. The 201-200-SP is used on 190-240VAC, 50/60Hz motors. The 201-200-SP-T-9 is a pin-for-pin replacement for a Time Mark; #260 Series voltage monitor. High voltage protection is included in the 201-200-SP-T-9. The unique microcontroller-based voltage and voltage-sensing circuit constantly monitors the voltage to detect harmful power line conditions. When a harmful condition is detected, the relay’s output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to an acceptable level and a specified amount of time has elapsed (restart delay). The trip delay prevents nuisance tripping due to rapidly fluctuating power line conditions.
77C-KW/HP
The 77C-KW/HP single-phase current and voltage monitor provides protection with voltage from 100–240 V ac and motor full load ampere range of 2–90 A (external CTs required above 90 A).
ISS-105
The ISS-105 is a “smart” five-channel intrinsically safe relay and pump controller. The ISS-105 can be configured for a wide variety of applications including alternating or non-alternating duplex, duplex separate pump stop (SPS), triplex and quadplex applications. It can be set up for pump-up or pump-down applications or can be used as a five-channel relay. The ISS-105 has a long list of features that are needed for multiple pump applications. The ISS-105 can indicate low, high and out-of-sequence alarms. If an out-of-sequence alarm occurs, the skipped pump(s) will be started as intended. The Model ISS-105 can be set up to do non-alternating control, alternating control and alternating control with one non-alternating pump. The non-alternating pump is intended for use with an emergency or jockey pump. The ISS-105 can start an emergency pump once every 50 cycles to keep it working freely. Using the built-in DIP switches, individual pumps can be disabled when taken out of service for repair or maintenance.
ALT-115-S-SW
The ALT alternating relays are used to alternate between two loads. The ALT is commonly used in duplex pumping applications to balance the runtime of both pumps. The ALT-S is used in single high-level float applications. When the float switch opens, the alternating relay changes state, forcing the other pump to run the next time the float closes. All ALT relays have a built-in debounce feature that prevents the relay from changing state if the switch or float contact bounces momentarily. The ALT-X has an internal cross-connected relay and is used in dual high-level float applications. These floats are commonly referred to as lead and lag floats. The pumps alternate as in the ALT-S version but the crossconnected relay configuration allows both pumps to run simultaneously when both the lead and lag floats are closed. These relays are also available with a built-in switch (SW option) that is used to manually force one of the pumps to run every time the float switch is closed. This is helpful when a pump has been removed for repair or for test purposes. In the case of the ALT-X-SW, the switch essentially forces one pump to be the lead pump, while still allowing the second to run when both floats are closed. Must use the OT08PC socket for UL Rating!
201-100-SP
The 201-xxx-SP is an 8-pin octal-base, plug-in voltage monitor designed to protect single-phase motors regardless of size. The 201-100-SP is used on 95-120VAC, 50/60Hz motors to prevent damage caused by low voltage. The 201-200-SP is used on 190-240VAC, 50/60Hz motors. The 201-200-SP-T-9 is a pin-for-pin replacement for a Time Mark; #260 Series voltage monitor. High voltage protection is included in the 201-200-SP-T-9. The unique microcontroller-based voltage and voltage-sensing circuit constantly monitors the voltage to detect harmful power line conditions. When a harmful condition is detected, the relay’s output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to an acceptable level and a specified amount of time has elapsed (restart delay). The trip delay prevents nuisance tripping due to rapidly fluctuating power line conditions.
201-200-SP-T-9
The 201-xxx-SP is an 8-pin octal-base, plug-in voltage monitor designed to protect single-phase motors regardless of size. The 201-100-SP is used on 95-120VAC, 50/60Hz motors to prevent damage caused by low voltage. The 201-200-SP is used on 190-240VAC, 50/60Hz motors. The 201-200-SP-T-9 is a pin-for-pin replacement for a Time Mark; #260 Series voltage monitor. High voltage protection is included in the 201-200-SP-T-9. The unique microcontroller-based voltage and voltage-sensing circuit constantly monitors the voltage to detect harmful power line conditions. When a harmful condition is detected, the relay’s output relay is deactivated after a specified trip delay. The output relay reactivates after power line conditions return to an acceptable level and a specified amount of time has elapsed (restart delay). The trip delay prevents nuisance tripping due to rapidly fluctuating power line conditions.
PC-200-LLC-GM
PC-200-LLC-GM is a liquid level control relay with an input voltage ac of 190–240 and an adjustable probe sensitivity from 4.7–100 kΩ.
ISS-100
The ISS-100 switches are UL 913 listed as an associated apparatus for interfacing between hazardous and non-hazardous areas. These units must be installed in a non-hazardous area.
ISS-101
The ISS-101 switches are UL 913 listed as an associated apparatus for interfacing between hazardous and non-hazardous areas. These units must be installed in a non-hazardous area.
ISS-102C-M-LC
The ISS-102 is a two-channel, intrinsically-safe switch designed for multiple uses including a pump-up/pump-down (latching) controller or two-channel switch. Two LEDs indicate the state of the intrinsically-safe inputs and output relays and user-selectable options are available including a variable resistance threshold for float inputs. The ISS-102 enclosure is surface or DIN rail mountable. -LC Each input channel is active when the corresponding switch is closed. When the lag input (CH2) is activated, the output closes. Applying latching logic, the output contact remains closed until the lead (CH1) and the lag (CH2) inputs are deactivated. Sensitivity is fixed at 100kOhms with a debounce time delay of 2 seconds. -DCS This dual-channel switch has a debounce delay feature of 0.5 seconds. Resistance probes or switches can be used on its inputs. Two LEDs illuminate the output state of either form A relay. Sensitivity is fixed at 100kOhms with a debounce time delay of 0.5 seconds. -MC By selecting the proper functionality through the dip switches, you can define a pump-up or pump-down, single or dual channel non-latching switch. The sensitivity adjustment (4.7k-100kOhms) allows you to define the input impedance at which the output relays (one form A & one form C) will change state, with a debounce time delay of 0.5 or 2 seconds.Frequently Asked Questions
What types of fuses does Littelfuse offer for industrial applications?
Littelfuse offers UL Class fuses, high-speed fuses, medium voltage fuses, 10 x 38 mm fuses, and solar fuses for industrial applications.
What are Littelfuse fuse blocks and holders designed for?
Littelfuse fuse blocks and holders are selected by OEMs and designers for their compact designs, indication features, and DIN-rail mounting flexibility.
What do POWR-BLOKS power distribution blocks provide?
POWR-BLOKS power distribution blocks offer a safe and convenient way to splice cables and manage power distribution requirements within panels and systems.
What is the purpose of Littelfuse feeder protection relays?
Feeder protection relays protect circuits from overcurrent, ground faults, phase loss, overload, and other detrimental conditions.
What is the Industrial Shock-Block® GFCI designed for?
The Industrial Shock-Block® GFCI is designed for people protection in industrial facilities and meets UL Standard 943C Class C and Class D.
How do high-resistance grounding systems benefit industrial applications?
High-resistance grounding limits point-of-fault damage and eliminates arc-flash hazards and transit overvoltages associated with ground faults.
What protection do Littelfuse voltage monitors offer?
Voltage monitors provide protection against both supply line and load side faults when the motor is running.
What functions do Littelfuse timers and flashers control?
Timers and flashers delay starting and stopping loads, and control cycling and sequencing of motors, pumps, compressors, heaters, and lighting.
How do Littelfuse arc-flash protection relays enhance safety?
Arc-flash relays detect a developing arc-flash incident and send a trip signal to interrupt power before significant damage occurs.
What types of motor protection does Littelfuse provide?
Littelfuse offers voltage monitors, current monitors, and Bluetooth enhanced overload relays for low and medium voltage motor protection applications.
Frequently Asked Questions about Littelfuse
What certifications and standards do Littelfuse products comply with?
Littelfuse products are certified to multiple international standards, including UL (Underwriters Laboratories), CSA (Canadian Standards Association), CCC (China Compulsory Certification), and EAC (Eurasian Conformity). Customers can verify specific product certifications by consulting individual product datasheets on Littelfuse.com, which provide comprehensive details about standards compliance for each component.
What industries and applications are Littelfuse products used for?
Littelfuse products are critical for electrical protection and safety across multiple industrial sectors, including manufacturing, automation, power distribution, and electrical control systems. Their comprehensive product portfolio serves industries that require robust electrical protection, including motor and pump applications, solar installations, programmable logic controllers (PLCs), electrical switch panels, and critical infrastructure environments. Key product lines protect against overcurrent, voltage transients, ground faults, and temperature-related electrical risks, ensuring equipment safety and operational reliability.
What technical support does Littelfuse offer?
Littelfuse offers comprehensive technical support through multiple channels. Their Technical Hotline (800-TEC-FUSE) provides direct access to engineers who can help identify issues and recommend solutions. Additionally, Littelfuse offers extensive online Technical Resources at Littelfuse.com, including datasheets, product manuals, whitepapers, application guides, and online design tools. Their experienced product and application engineers also provide step-by-step support from design to installation.
What are the main product lines offered by Littelfuse?
Littelfuse offers comprehensive industrial protection and control product lines, including fuses, fuse holders, protection relays, temperature sensors, and electrical safety components. Their key product categories span surge protective devices, custom OEM products, electrical switch panels, medium voltage fuses, ground-fault protection relays, motor and pump protection devices, and temperature sensors. These products are designed to minimize electrical safety hazards, limit equipment damage, improve productivity, and safeguard personnel from electrical faults.
What are the key features of Littelfuse products?
Littelfuse products feature exceptional circuit protection technologies with key characteristics including UL/IEC safety standard compliance, low internal resistance, and advanced protective capabilities across multiple product lines. Their components provide critical protection for industrial systems, offering features like overcurrent protection, voltage transient suppression, and resettable protection devices with ultra-low resistance and compact designs. Key product lines include fuses, metal oxide varistors (MOVs), TVS diodes, PolySwitch devices, and specialized electronic protection components that enhance system reliability and safety.
What environmental ratings do Littelfuse products have?
Littelfuse products feature comprehensive environmental ratings, including NEMA Type 1, 2, 3, 3R, 4/4X, 12, and 13 certifications, as well as IP65 protection. These ratings ensure superior protection in diverse industrial environments, with an operating temperature range of -40°F to +131°F (-40°C to +55°C). Many products also include UV-stabilized materials and neoprene gaskets for enhanced durability in outdoor and challenging conditions.
What accessories are available for Littelfuse products?
Littelfuse offers several key accessories across their product lines, including fuse holders, voltage monitoring modules, and terminal connectors. Specific accessories include the LPSM003ZXID (indicating) and LPSM003Z (non-indicating) POWR-SAFE Dead Front fuse holders for Class CC and Midget-Style fuses, the VRM6048 voltage monitor accessory module, and female quick connect terminals (P1015 series) in various wire gauge sizes. These accessories are designed to enhance protection, monitoring, and connectivity for Littelfuse electrical components.
What is Littelfuse's warranty policy?
Littelfuse provides comprehensive warranty details on their official website at www.littelfuse.com/warranty. Customers should visit this page to review the specific warranty terms and conditions for their specific product lines. For direct warranty support or questions, customers can contact Littelfuse Technical Support at 1-800-TEC-FUSE or email [email protected].
What communication protocols do Littelfuse products support?
Littelfuse supports a comprehensive range of industrial communication protocols, including PROFIBUS, PROFINET, EtherNet/IP, DeviceNet, Modbus RTU, and CANopen. Our products provide flexible connectivity solutions across multiple industrial automation platforms, enabling seamless integration with various control systems and network architectures.
How are Littelfuse products typically installed?
Littelfuse products are typically installed using specialized mounting hardware like fuse holders, blocks, and panels designed for specific industrial applications. The POWR-SAFE Dead Front holders, for example, provide optimum protection for Class CC and Midget-Style fuses, supporting installations up to 600 VAC/DC. Installation often involves using precision terminals with strain relief, such as 0.25 in. female quick connect terminals, to ensure secure and safe electrical connections in industrial control systems.