Crouzet Relay Sizing for SEA Panels (2026)

Crouzet Relay Sizing for Southeast Asian Panels: A 2026 Sourcing Guide

By the AoCtrl Sourcing Desk, procurement editorial team
Data through September 9, 2026

The fastest way to specify a Crouzet relay stack is to separate three jobs that are often combined in one bill of materials. Use a phase monitor to qualify the incoming supply, use a current monitor to supervise the load, and use a solid-state relay to switch the load. Selecting one device for all three jobs leaves the panel builder without a clear answer to two basic questions: what must stop the machine, and what is allowed to continue operating?

That distinction matters because a panel may be installed on a nominal 220 VAC network, a nominal 400/440 VAC system, or equipment whose control card provides a different DC command range. The catalog in this guide gives panel builders six concrete Crouzet starting points: PWRA220A and DIRT110A monitoring relays plus 84137140N, GNR30DCZH, GNR45DCZP, and 84137121N zero-cross solid-state relays.

Why is the relay chain getting more attention in 2026?

Relay selection is no longer only a matter of finding a device with a matching coil voltage. Buyers are building documented supply chains for motor, HVAC, pumping, and conveyor equipment, and the market research now tracks the two functions separately.

On September 5, 2026, Fact.MR projected the semiconductor relay switches market from USD 1.7 billion in 2026 to USD 3.4 billion by 2036, a 7.3% CAGR. One day earlier in the research cycle, on September 1, 2026, Future Market Insights valued the current monitoring relays market at USD 1.1 billion in 2026 and forecast USD 2.0 billion by 2036, a 5.7% CAGR. These are different device families, but they meet at the same cabinet boundary: a control decision on one side and a switched load on the other.

Crouzet's current market position matches that boundary. As of September 9, 2026, Crouzet's official monitoring-relay page states that its relays protect AC motors, HVAC systems, pumps, and conveyors by continuously monitoring phase, voltage, current, and level. For a panel shop, that is a useful product-scope statement, but it is not a substitute for a point-by-point load schedule. The purchase order still has to identify what is being measured, what action follows, and how the output reaches the next device.

What should a Crouzet relay specification include before RFQ?

Start with six fields. They can prevent most substitutions from being reviewed on the wrong basis:

Monitored quantity: phase loss, phase sequence, AC current, or another quantity.
Supply and load voltage: distinguish the relay's supply from the switched load.
Output form: electromechanical SPDT relay or zero-cross solid-state output.
Command range: the DC control voltage that will drive the SSR.
Mounting and termination: DIN rail with screw terminals, socket, or fixed screw connection.
Commercial request: MPN, quantity, destination, target delivery window, and any approved alternates.

MOQ, current availability, and lead time should not be inferred from a market forecast. They are confirmed against the current offer and the requested quantity. Submit each MPN as a separate RFQ line so that a phase monitor, a current monitor, and an SSR are not merged into one commercially ambiguous item.

Which Crouzet device handles phase loss and phase sequence?

PWRA220A is the direct starting point when a three-phase supply must be checked for phase loss or phase sequence. Its catalog record identifies a WRA-series phase-loss and phase-sequence monitor with a 3 x 220 VAC supply, an SPDT relay output, a 10 A at 250 VAC contact rating, socketable mounting, and an operating range of -10 °C to 60 °C.

That combination is important for a panel schedule. The 3 x 220 VAC figure is the supply condition, not the rating of a universal replacement. The SPDT output gives the designer a defined relay interface for the next control decision, while the 10 A contact rating belongs to the monitoring relay's output contact. Neither number should be copied into the SSR line.

Use the device as the supply-quality gate. The installer can wire the monitored three-phase supply to the WRA device, connect the SPDT output to the panel's permissive or trip circuit, and keep the SSR command separate. Before approving a substitute, compare phase thresholds, terminal arrangement, reset behavior, mounting, and the exact monitored-voltage value. A part with the same output type is not automatically a functional alternate.

Which Crouzet device monitors motor current?

DIRT110A is the catalog starting point for an AC current-sensing monitor. The product record lists a 110 VAC supply, two AC trip ranges, an adjustable delay, an SPDT relay output, and a 10 A at 250 VAC contact rating. Its stated AC trip ranges are 0.035 to 7.07 A AC and 0.05 to 10 A AC, with a 0.1 to 10 second delay. It is designed for DIN-rail mounting and operates from -10 °C to 60 °C.

For a conveyor, pump, or fan panel, this is the component that should be evaluated against the load's normal operating band and the action desired after an abnormal reading. A current monitor does not replace a protective device selected for the installation, and its contact rating should not be treated as the load-switching rating. The clean panel architecture is to let the current relay make the supervisory decision, then command the output stage through the approved control interface.

The two listed trip ranges are useful during substitution review because they force a decision about range rather than a loose “current relay” description. The delay range also belongs in the comparison. If a 0.1-second setting is available but the application needs a longer start allowance, the panel designer needs to resolve that before purchase instead of discovering it during commissioning.

Which Crouzet SSR fits a high-current load?

84137140N is the highest-current SSR in this catalog slice. It is a GN-series zero-cross solid-state relay with a 100 A maximum load current and a 660 V maximum load voltage. The stated load range is 48 to 660 V, the control range is 4 to 32 V, and termination is by screw. Its catalog dimensions are 44.5 x 29.1 x 59.4 mm.

The part is best approached as a power-stage candidate, not as a universal “100 A relay” label. The 100 A figure is the catalog load-current maximum, while the 660 V figure is the catalog load-voltage maximum. Both must be read with the actual panel voltage, load type, grouping, enclosure, and thermal plan. The control side is 4 to 32 V, which is the range the upstream control circuit must be able to provide.

For a panel builder comparing footprints, the dimensions are useful early in the layout process. A device can be electrically plausible and still be a poor mechanical choice. Put the actual terminal orientation, creepage requirements, enclosure ventilation, and the supplier's mounting recommendation into the engineering review before the BOM is frozen.

Which Crouzet SSR is the compact DIN-rail option?

GNR30DCZH uses a different form factor. It is a GNR-series zero-cross solid-state relay for DIN-rail mounting, with a 30 A maximum load current, a 660 V maximum load voltage, a 48 to 660 V load range, a 4 to 32 V control range, and screw terminals. The catalog dimensions are 22.5 x 90 x 98 mm.

This is the more natural first look when a panel design already uses a 22.5 mm DIN-rail device pattern and the load requirement fits 30 A. The narrow module format can simplify cabinet planning, but it should not be selected by width alone. Compare the complete envelope, terminal access, load rating, control range, and the relay's suitability for the intended load with the same discipline used for a larger panel-mounted device.

The zero-cross designation is a useful comparison field because it distinguishes this output mode in the product family. It does not remove the need to document the command source, the load voltage, and the protective scheme. Those values remain part of the RFQ record even when the product family appears familiar.

When does GNR45DCZP become the better candidate?

GNR45DCZP is a GNR+ zero-cross solid-state relay with a 45 A maximum load current and a 500 V maximum load voltage. Its catalog load range is 24 to 500 V, the control range is 4 to 32 V, termination is by screw, and mounting is DIN rail. The listed dimensions are 45 x 90 x 98 mm.

The key difference is not simply “45 A instead of 30 A.” The lower 500 V load maximum and the 24 V lower end of the load range change the review. That makes GNR45DCZP a candidate for a different load envelope, not a drop-in upgrade to the 660 V GNR30DCZH. A panel BOM should keep the two lines separate and name the actual load voltage in each application.

The 4 to 32 V control range is shared with GNR30DCZH, which is helpful when the control architecture is stable. It still does not prove that the devices are interchangeable: the load limits, dimensions, family, and terminal details all matter. The right comparison is application to application, with the monitored supply and load values attached to each line.

Where does 84137121N fit?

84137121N is a GN-series zero-cross solid-state relay with a 50 A maximum load current and a 660 V maximum load voltage. Its load range is 48 to 660 V, its control range is 20 to 265 V, and it uses screw termination. The catalog dimensions are 44.5 x 29.1 x 59.4 mm.

The broad 20 to 265 V control range makes this the part to investigate when the upstream command source does not match the 4 to 32 V pattern of 84137140N, GNR30DCZH, or GNR45DCZP. It is not automatically the better choice. A wider control range can simplify an interface, but the panel team still has to check the load range, mounting, protection, and the exact command waveform or switching behavior required by the control system.

Its 50 A load maximum sits between the 30 A DIN-rail option and the 100 A GN option. That middle position can be useful in a two-tier sourcing strategy: one DIN-rail family for the normal branch and one higher-current device for the power branch. The point is to document why each device is present rather than buying several nearly similar parts.

How should a panel shop build the protection chain?

Use a three-stage review:

Stage 1: qualify the supply

Start with PWRA220A when the requirement is a 3 x 220 VAC phase-loss or phase-sequence check. Record the monitored supply, the output contact rating, the reset arrangement, and how the permissive signal reaches the control circuit.

Stage 2: supervise the load

Use DIRT110A when the requirement is AC current supervision. Record the selected trip range, delay, operating temperature expectation, and whether the SPDT output is used for alarm, trip, or permissive control.

Stage 3: switch the load

Choose the SSR from the actual load range, control range, mounting method, and current requirement:

84137140N: 100 A maximum, 660 V maximum, 4 to 32 V control, screw termination.
GNR30DCZH: 30 A maximum, 660 V maximum, 4 to 32 V control, DIN rail, 22.5 mm module width.
GNR45DCZP: 45 A maximum, 500 V maximum, 4 to 32 V control, DIN rail, 45 mm module width.
84137121N: 50 A maximum, 660 V maximum, 20 to 265 V control, screw termination.

The devices should not be treated as interchangeable based on family name or the phrase “solid-state relay.” The final selection must match the actual 220, 400, or 440-class system shown on the panel drawing, the control signal available from the PLC or controller, and the enclosure's mechanical plan.

What should an RFQ packet contain?

A useful RFQ avoids the common “please quote equivalent” message. Include:

The exact MPN and the function required.
Panel supply voltage, load voltage, and control-command voltage.
Load type, normal current, maximum current, and any inrush information available to the buyer.
Required switching function and output type.
DIN-rail, socket, or panel-mounting requirement.
Quantity, ship-to country, Incoterm expectation, and target date.
Approved-alternate rules, including which deviations require engineering approval.

For a mixed cabinet, send the phase monitor, current monitor, and SSR on separate lines. The commercial desk can then confirm MOQ, availability, packaging, and the quantity available for the requested destination without hiding a functional change inside a bundle.

Which MPN should a buyer shortlist first?

There is no single winner because each MPN answers a different question:

Shortlist PWRA220A for a 3 x 220 VAC phase-loss or phase-sequence gate.
Shortlist DIRT110A for AC current supervision with a 0.1 to 10 second delay range.
Shortlist 84137140N for a 100 A, 660 V maximum screw-terminated SSR candidate.
Shortlist GNR30DCZH for a 30 A, 660 V maximum DIN-rail module with a 4 to 32 V control range.
Shortlist GNR45DCZP for a 45 A, 500 V maximum DIN-rail module with a 4 to 32 V control range.
Shortlist 84137121N for a 50 A, 660 V maximum screw-terminated SSR when the control source may require 20 to 265 V.

That shortlist is more useful than a single “best” recommendation. It turns a vague purchase request into six traceable engineering decisions and lets the sourcing team compare commercial terms without changing the technical requirement in the background.

What can a sourcing desk confirm before shipment?

Before approving a purchase order, ask for confirmation of the exact MPN, the terminal and mounting format, the stated voltage and current ranges, the quantity available for the requested destination, the MOQ, and the current lead-time basis. For an approved alternate, request the same information and mark every difference for engineering review.

At the panel-builder level, the final commissioning record should identify which relay performed the supply check, which device performed current supervision, and which SSR switched the load. That record makes fault finding faster and gives the next RFQ a stable set of requirements.

Data Notes and sourcing limitations

This guide uses the AoCtrl catalog evidence for six Crouzet MPNs and three dated market or manufacturer pages. The catalog figures are product-record figures, not a statement of current stock, MOQ, or delivery time. Market forecasts are directional planning data, not a purchase commitment. No substitute should be approved from an MPN name alone. Verify the complete electrical, mechanical, environmental, and commercial requirements with the selected supplier and the machine designer.

AoCtrl is an independent industrial automation distributor and not an authorized distributor or manufacturer representative. Product names, specifications, and availability can change. Request current drawings and supplier confirmation before issuing a production order.

Frequently asked questions

Can PWRA220A replace a current monitor?

No. PWRA220A is identified as a phase-loss and phase-sequence monitor with a 3 x 220 VAC supply. DIRT110A is the current-monitoring candidate in this catalog slice. They supervise different quantities and should be specified as different functions.

Can I use an SSR in place of a phase monitor?

No. The zero-cross SSRs listed here are output devices. PWRA220A is the device identified for phase-loss and phase-sequence monitoring. An SSR can carry out a command; it does not establish that the three-phase supply meets the phase condition.

Is the 100 A MPN always better than the 30 A MPN?

No. 84137140N has a 100 A maximum load current, while GNR30DCZH has a 30 A maximum. The correct choice also depends on load voltage, control range, mounting, dimensions, protection, and the actual application requirement.

Why keep the two DIN-rail SSRs separate?

GNR30DCZH lists 30 A and 660 V maximums, while GNR45DCZP lists 45 A and 500 V maximums. Their load envelopes are different. Keeping separate lines protects the panel specification from a higher-current but lower-voltage substitution.

What is the safest way to request an equivalent?

Provide the exact monitored function, supply voltage, load voltage, control voltage, output type, mounting, current requirement, quantity, destination, and lead-time target. Mark every proposed difference for engineering approval. That keeps a commercial alternative from becoming an undocumented design change.