Allen-Bradley 700-HLT1Z24 — 24V DC Relay Specs & Buying Guide

By Abdullah Zahid
14 min read
Allen-Bradley 700-HLT1Z24 24V DC slim terminal block interface relay mounted on DIN rail in industrial control panel

Allen-Bradley 700-HLT1Z24 24V DC GP Terminal Block Relay – Specs, Pricing and Selection Guide

If you are a controls engineer or panel builder specifying interface relays for a Rockwell-based system, the Allen-Bradley 700-HLT1Z24 is likely already on your BOM shortlist. This 24 V DC slim terminal block relay delivers a single SPDT (1 C/O) electromechanical output rated up to approximately 6 A at 250 V AC-1, packaged in a touch-safe, 6.2 mm wide DIN-rail module that fits cleanly into high-density I/O panels. The real question at this stage is not what it is — it is whether this exact catalog number matches your coil voltage, pole count, and load requirements, and whether it is in stock when you need it.

If you have already confirmed this is the right part, check current pricing and availability for the Allen-Bradley 700-HLT1Z24 at LeadTime.ca — ships worldwide.

Who Should Buy the 700-HLT1Z24 — and Who Shouldn't

This relay is the right choice for engineers and panel builders who need a slim, DIN-rail-mounted interface relay within a 24 V DC control architecture. It belongs in your design if all of the following are true:

  • Your control system supplies 24 V DC to relay coils — not 24 V AC, 120 V AC, or any other voltage.
  • Your application requires a single-pole changeover (SPDT / 1 C/O) contact only.
  • Your switched load current falls within the relay's rated operational current of approximately 6 A at 250 V AC-1.
  • Panel space is a constraint and the 6.2 mm slim terminal-block form factor is an asset.
  • Your project or plant standard specifies Allen-Bradley hardware, UL/CSA approvals, and touch-safe screw terminals.

If you need a 2-pole output, a higher current rating, an AC coil, or a more cost-competitive generic relay, this is not the right part. The 700-HLT2Z24 is the 2-pole variant for circuits requiring dual contacts, and other coil-voltage variants exist within the 700-HL family for AC control systems.

On this page:

What the 700-HLT1Z24 Actually Does in a Control Panel

The Allen-Bradley 700-HLT1Z24 is a member of the Allen-Bradley Bulletin 700-HL Slim Terminal Block Interface Relay family. Its job is straightforward and critical: it sits electrically between a low-voltage control signal — typically a PLC digital output card or a controller — and a field device such as a solenoid valve, contactor coil, indicator lamp, or small motor starter. The relay provides galvanic isolation so that transients, inrush currents, and voltage spikes on the field side do not reach and degrade expensive I/O cards.

Unlike plug-in relay bases that require a separate socket, the 700-HLT1Z24 integrates the relay and terminal block into one slim module with screw terminals directly on the unit. This reduces component count, eliminates the socket-to-relay contact interface, and results in a cleaner, more compact panel layout. The touch-safe construction means terminals are safe to approach during live testing, which matters on the commissioning floor and during maintenance. The 6.2 mm width is a genuine differentiator when you are mounting twenty or thirty interface relays side by side on a DIN rail and every millimetre counts.

The electromechanical SPDT output gives you a common terminal plus one normally open and one normally closed contact, giving designers flexibility in how interlocks and logic circuits are wired. A 24 V DC coil is the industry standard in modern PLC-based panels, and the 700-HLT1Z24 is built precisely around that control voltage.

Typical System Architecture and Signal Chain

The 700-HLT1Z24 occupies the interface layer between the controller and the field, converting a low-energy logic signal into a switched contact capable of handling real-world loads.

  • PLC or controller digital output card supplies 24 V DC to energize the relay coil via terminals A1 and A2.
  • The 700-HLT1Z24 mounts on a 35 mm DIN rail inside the control enclosure alongside other interface relays grouped by function or voltage zone.
  • The SPDT contact terminals (common / normally open / normally closed) connect to the field load circuit — solenoid valve, contactor coil, lamp, or interlock.
  • Upstream fusing or circuit protection on the load side protects the relay contacts and downstream wiring from fault conditions.
  • Optional surge suppression devices on inductive loads connect at the load terminal to protect contact life and upstream electronics.

Where Engineers Deploy the 700-HLT1Z24

The most common deployment is interfacing PLC digital output cards to 24 V DC solenoid valves, small contactor coils, and pilot lamps in machine control panels. The relay isolates the I/O card from field-side transients, extending the life of the control hardware and providing a clearly defined switching point that technicians can probe and test independently of the PLC.

OEM machine builders who standardize on Allen-Bradley controls use the 700-HLT1Z24 in high-density relay panels where multiple interface points are needed in minimal panel width. Packaging lines, material handling conveyors, and food and beverage equipment frequently use banks of 700-HL relays for exactly this reason — the 6.2 mm slim format lets builders install many channels in a compact enclosure without expanding the panel footprint.

Retrofit and modernization projects are another strong use case. When older panels with bulkier plug-in relay sockets are refurbished, engineers often replace legacy relays with 700-HLT1Z24 units to save space and align the installation with current Allen-Bradley documentation and spare-parts standards. The SPDT contact also supports status and logic interlock circuits in machine safety and sequencing schemes.

Water and wastewater control panels, process skids, and building automation panels in facilities running Allen-Bradley hardware regularly specify the 700-HL family for the same reasons: standardization, compact layout, and availability through established distributor channels.

Application Typical Deployment
OEM machine panel, factory automation High-density DIN-rail relay bank interfacing PLC outputs to solenoids and contactors
Material handling conveyor controls Individual relay per output channel for isolation and fault isolation per zone
Food and beverage packaging lines Slim relay modules grouped by machine section to keep enclosure width minimal
Panel retrofit / modernization Replacing legacy plug-in relays to recover panel space and standardize on A-B parts
Process skids and modular equipment Signal isolation between skid-mounted PLC and field instruments or actuators
Water/wastewater and building automation Interface layer in Allen-Bradley-standardized facilities for control and interlock circuits

Key Specifications and Variant Comparison for the 700-HLT1Z24

Specification Value
Brand / Manufacturer Allen-Bradley (Rockwell Automation)
Catalog Number 700-HLT1Z24
Product Family Bulletin 700-HL Slim Terminal Block Interface Relay
Coil Voltage 24 V DC nominal
Contact Configuration 1 x SPDT (1 C/O)
Rated Operational Current Up to approx. 6 A at 250 V AC-1
Width Approx. 6.2 mm
Mounting 35 mm DIN rail
Terminal Type Screw terminals, touch-safe construction
Approvals UL listed, CSA certified, CE marked (where applicable)

Full technical specifications are available on the product page at LeadTime.ca.

The 700-HL family covers multiple catalog variants. Understanding the differences prevents the most common ordering mistakes:

Catalog Number Coil Voltage Contact Configuration When to Choose
700-HLT1Z24 24 V DC 1 x SPDT (1 C/O) Standard choice for 24 V DC PLC output interfacing with single-pole switching
700-HLT2Z24 24 V DC 2 x SPDT (2 C/O) When two independent switched contacts are required from the same coil
700-HL AC coil variants AC coil voltage (e.g., 120 V AC) 1 or 2 C/O (model-dependent) When control voltage is AC — do not substitute for 24 V DC coil versions

If your circuit design calls for two contacts from a single relay, the 700-HLT2Z24 is the correct choice — check current availability and variant options at LeadTime.ca.

Expert Verdict: Is the 700-HLT1Z24 Worth Specifying?

For controls engineers and OEM panel builders working within a Rockwell Automation ecosystem, the Allen-Bradley 700-HLT1Z24 earns its place on the BOM. The slim 6.2 mm format, touch-safe screw terminals, and native Allen-Bradley documentation make it genuinely easier to design, build, and maintain compared with bulkier alternatives. The verified contact rating of approximately 6 A at 250 V AC-1 covers the vast majority of solenoid valve, contactor coil, and pilot lamp loads that interface relays are asked to switch. When you are standardizing across a fleet of machines or managing a facility's spare-parts inventory, having every interface relay from the same family with consistent documentation, consistent terminal layouts, and consistent approvals is a real operational advantage. The 700-HLT1Z24 delivers all of that in a package that fits 24 V DC control architectures cleanly.

Where the 700-HLT1Z24 is the wrong answer: if your project is cost-sensitive and plant standards permit generic interface relays, the price premium over third-party slim relays from other manufacturers can add up across a large panel build. If you need two switched contacts from a single coil, you need the 700-HLT2Z24 — not this part. And if your control voltage is anything other than 24 V DC, you must select the correct coil-voltage variant from the 700-HL family. None of these are criticisms of the relay itself; they are simply the ordering decisions that matter most before you commit to a purchase.

From a procurement standpoint, the 700-HLT1Z24 is a well-stocked part at major distributors serving North America and markets worldwide, but availability does fluctuate with project demand. One detail that catches buyers off guard: the manufacturer designates 700-HLT1Z24 as a 10-piece pack at the catalog level. Confirm with your distributor whether they sell individual units or full packs, and align your order quantity with your actual needs before placing the order. Buying through a specialist industrial distributor rather than a generic catalog channel means you get confirmation of coil voltage, pack quantity, and realistic lead time before the order ships — reducing the risk of a costly wrong-part return. View current pricing and stock status for the 700-HLT1Z24 at LeadTime.ca.

For volume pricing or to confirm lead time before committing to a panel build, contact the LeadTime.ca team directly — we ship worldwide.

What Engineers in the Field Are Saying About the 700-HL Family

Across forums including PLCTalk, PLCS.net, MrPLC, r/PLC, r/automation, and distributor Q&A sections, discussion of the 700-HL family at the specific model level is limited — most community conversation happens at the family level. That said, the recurring themes are consistent and useful for anyone specifying this part for the first time.

The most frequent praise centres on the slim footprint. Panel builders report that the ability to mount these relays at 6.2 mm spacing lets them pack significantly more interface channels into the same DIN rail length compared with bulkier plug-in relay alternatives. Technicians and electricians consistently single out the touch-safe screw terminals and clear markings as genuine time-savers during wiring and maintenance — fewer errors, faster commissioning, and cleaner-looking panels. Users who apply these relays within their rated current range and with proper load protection report reliable, long-service-life operation.

The recurring complaints are worth taking seriously. Cost is the most cited concern: buyers who price the 700-HLT1Z24 against generic slim relays from non-A-B sources regularly note the price difference, particularly on large panel builds. The second recurring complaint is ordering the wrong coil voltage — the 24 V DC and 24 V AC versions look similar in catalog listings and the catalog number suffixes are easy to misread under time pressure. Several users report receiving incompatible parts and facing installation delays as a result. A smaller but consistent thread of complaints involves premature contact wear when relays were switching heavy inductive loads — motor and solenoid loads — without adequate surge suppression or when the relay was operated continuously near maximum ratings. The fix in every case is the same: confirm load characteristics against the datasheet contact ratings, add suppression on inductive loads, and do not treat the maximum rating as a continuous operating point.

Wiring and Installation Overview for the 700-HLT1Z24

Always refer to the manufacturer's official datasheet and wiring diagram for full installation procedures. The following overview covers the key requirements an engineer should verify before and during installation:

  • Mount the relay securely on a grounded 35 mm DIN rail; confirm the rail is properly grounded in the control enclosure before populating with relays.
  • Connect 24 V DC control supply to the coil terminals (A1/A2), observing polarity as required by the datasheet; incorrect polarity on a DC coil is a common installation error that prevents energization.
  • Wire the SPDT contact terminals — common, normally open, and normally closed (typically numbered per the relay's terminal marking scheme) — strictly according to the approved control schematic.
  • Tighten all screw terminals to the torque value specified in the datasheet and perform a tug-test on each conductor before powering up.
  • Verify that upstream fusing or circuit protection is in place for the load side, and install surge suppression devices on any inductive loads before commissioning.

Compatible Accessories and System Expansion

The Allen-Bradley Bulletin 700-HL family is designed for grouped DIN-rail mounting and is compatible with standard 35 mm DIN rail hardware. When building out a relay panel using the 700-HLT1Z24, consider the following related components:

  • 35 mm DIN rail sections and end brackets — standard panel mounting infrastructure compatible with the 700-HL slim module format.
  • Surge suppression devices for inductive loads — essential for protecting contact life when switching solenoid valves, contactor coils, or relay coils; specify devices matched to the load voltage and type.
  • Terminal block markers and labelling systems — the 700-HL's clear terminal layout accommodates standard DIN-rail marker strips for circuit identification.
  • 700-HLT2Z24 — the 2-pole (2 C/O) variant for applications requiring two switched contacts from a single 24 V DC coil; directly related and often stocked alongside the 700-HLT1Z24.
  • Upstream fusing and circuit protection components appropriate to the load current and enclosure design — plan these during the panel design phase, not as an afterthought.

Wrong-Part Prevention Checklist Before Ordering the 700-HLT1Z24

The following checklist should be completed before submitting a purchase order or placing this part number on a BOM. These checks address the most common and most costly ordering mistakes for this relay family:

  1. Confirm coil voltage: 24 V DC (do not mix with 24 V AC or 120 V AC versions).
  2. Verify contact form: SPDT / 1 C/O; if you need 2 contacts, this is not suitable.
  3. Check contact current rating against your load (motor inrush, lamp loads, inductive loads).
  4. Ensure physical style matches design: 6.2 mm slim terminal block relay for DIN rail, screw terminals, touch-safe.
  5. Verify that the plant standard actually specifies 700-HL family, not a different A-B relay family (e.g., 700-HK, 700-HB).
  6. Check packaging expectations: catalog 700-HLT1Z24 is a 10-piece package at the manufacturer level; confirm if distributor sells by unit or box.
  7. Confirm the relay's function (interface / isolation) fits your application and that any required external protection (fuses, breakers, surge suppression) is planned.
  8. Ensure ambient temperature and approvals from the datasheet comply with project or customer specs.

If any of these checks raise a question, contact LeadTime.ca before ordering — our team can confirm coil voltage variants, pack quantities, and current lead times to prevent a wrong-part shipment.

Frequently Asked Questions

Can the 700-HLT1Z24 switch both AC and DC loads, and are there different ratings for each?

Yes, the SPDT contact can switch both AC and DC loads, but the current and voltage limits differ by load type and utilization category. The relay carries a rated operational current of approximately 6 A at 250 V AC-1 for general-purpose AC loads. DC load ratings are typically lower due to arc suppression differences. Always consult the manufacturer's datasheet for the specific utilization category (AC-1, AC-15, DC-13, etc.) that matches your load type, and never assume AC ratings apply directly to DC applications.

Is the 700-HLT1Z24 sold as a single relay or only in packs of 10?

At the manufacturer catalog level, 700-HLT1Z24 is designated as a 10-piece package. Individual distributors may sell the relay as single units, but this varies. Confirm with your distributor before ordering — and align your internal BOM and ERP material master with the actual pack size to avoid over- or under-ordering, particularly for spares inventory.

What is the difference between the 700-HLT1Z24 and the 700-HLT2Z24?

The 700-HLT1Z24 provides a single SPDT (1 C/O) contact output. The 700-HLT2Z24 is the 2-pole version, providing two independent SPDT contacts from the same 24 V DC coil. If your circuit design requires two switched outputs — for example, switching two independent load circuits simultaneously — the 700-HLT2Z24 is the correct part. Using the 700-HLT1Z24 where two contacts are needed is a common design error that is caught during commissioning, not before shipping.

Can I replace an older plug-in style Allen-Bradley relay with the 700-HLT1Z24 to save panel space?

The 700-HLT1Z24 is a terminal-block style relay, not a plug-in relay, so it is not a direct mechanical swap for a plug-in relay base. A retrofit requires remounting on DIN rail and rewiring to the screw terminals. That said, many engineers do exactly this during panel modernizations specifically to recover panel width and simplify wiring. The key checks are that the coil voltage, contact configuration, and current ratings of the new relay match the application requirements of the legacy relay being replaced.

What surge suppression is recommended when switching inductive loads?

Inductive loads — solenoid valves, contactor coils, relay coils — generate voltage transients when de-energized that accelerate contact wear and can damage upstream electronics. Surge suppression devices should be fitted directly at the load terminals or across the load. The type of suppressor (RC snubber, varistor, diode, or Zener) depends on whether the load circuit is AC or DC and the load voltage. Refer to the Allen-Bradley datasheet and Rockwell application documentation for specific suppression guidance, and always plan suppression during the design phase rather than adding it after contact failures appear.

What do I do if the 700-HLT1Z24 coil is not energizing after installation?

First, measure the voltage present at the coil terminals A1 and A2 under the commanded-on condition — confirm it is within the 24 V DC operating range specified in the datasheet. If voltage is present and the relay does not actuate, check for reversed polarity on the DC coil. If voltage is absent, trace the control circuit back to the PLC output card or control source. If the coil is confirmed good but the relay still fails, inspect for mechanical damage and replace with a known-good unit. If the replacement also fails to energize, the fault is in the control circuit, not the relay.

Why Order the 700-HLT1Z24 From LeadTime.ca

  • LeadTime.ca ships worldwide — buyers in North America and internationally can source the 700-HLT1Z24 and related 700-HL family variants through a single specialist distributor.
  • Specialist distributor knowledge means coil voltage variants, pack quantities, and relay family cross-references are confirmed before the order ships — reducing wrong-part risk.
  • Volume pricing is available for panel builds requiring multiple packs; contact the team directly for project-level quotes.
  • Hard-to-find and short-lead-time industrial parts are a core focus — LeadTime.ca sources Allen-Bradley components including less common 700-HL variants that generic channels may not stock.

At-a-Glance Summary

  • Catalog number: 700-HLT1Z24 — 24 V DC GP Terminal Block Relay, Bulletin 700-HL family.
  • Coil voltage: 24 V DC nominal — not compatible with AC control systems without selecting the correct AC coil variant.
  • Contact output: 1 x SPDT (1 C/O) — single-pole changeover only; 700-HLT2Z24 is the 2-pole alternative.
  • Rated operational current: approximately 6 A at 250 V AC-1 — confirm load type against datasheet utilization categories.
  • Physical format: 6.2 mm slim terminal block module on 35 mm DIN rail with touch-safe screw terminals.
  • Approvals: UL listed, CSA certified, CE marked where applicable.
  • Manufacturer packaging: 10-piece pack at catalog level — confirm per-unit vs. per-pack pricing with distributor before ordering.
  • Key ordering risks: wrong coil voltage variant, wrong pole count, exceeding contact current rating on inductive loads without suppression.
  • Ships worldwide through LeadTime.ca — pricing available on the product page; contact for volume quotes and lead-time confirmation.

You may also be interested in: