Circutor computer SMART III Fast 6 Static PF Controller

A 6-step regulator for fast static switching of capacitor banks

The Circutor computer SMART III Fast 6 (code R13951) is a power factor regulator for static switching with 6 transistor outputs and EMF or EMB switching units. Circutor positions it for loads that change quickly, between 40 ms and 4 seconds, and for large unbalances between phases, such as welding units, cranes, lifts, smelters, hospitals and the automotive industry.

Like the standard SMART III it can use one or three current transformers, works as an integral power analyzer, controls residual leakage current, offers alarms and capacitor testing, and supports up to four objective cos phi values. It is a fast-switching sibling of the contactor models rather than a replacement for them.

computer SMART III Fast 6 functions

• 6 steps through opto-MOSFET transistor outputs for EMF or EMB static switching modules
• Compensates loads varying between 40 ms and 4 seconds, and unbalanced single-phase loads such as welding
• 1 or 3 current transformer measurement; input …/5 A or …/1 A
• Wide supply and measuring range of 100 to 520 Vac; low 8 to 14 VA consumption
• Leakage current measurement 0.01 to 1.5 A; two potential-free digital inputs
• Modbus RTU over RS-485; alarm relay; fan relay
• Up to four objective cos phi targets; capacitor test and alarm programming

computer SMART III Fast 6 technical specifications

Identification and supply

Measurement

Inputs, outputs and interface

Mechanical and environmental

Fast 6 versus the other Fast models

The datasheet covers four static-switching regulators: Fast 6 (R13951., EMF/EMB), Fast 12 (R13962., EMF/EMB), F6-12Vdc (R13953., EMB-2PH) and F12-12Vdc (R13964., EMB-2PH). The Fast 6 drives its modules with 24 Vdc opto-MOSFET outputs for EMF or EMB switching units, while the 12 Vdc models give a 12 V output for EMB-2PH units. Pick the step count and the static-switch module that matches your bank design; a regulator and static switch must be chosen together.

Installation and operation notes

Use a 144 x 144 mm panel cut-out and keep within the IP51 front rating. Because static switching reacts in tens of milliseconds, the regulator needs correct CT polarity and phase selection; the three-CT option is recommended by Circutor for single-phase fast-changing loads such as welding. Plan thermal management of the static modules separately. The regulator also offers a fan output and an alarm relay.

Where the Fast 6 is used

Circutor lists welding units, cranes, lifts and hoists, smelters, hospitals and the automotive sector. A contactor regulator is cheaper where loads change slowly; the Fast regulator is intended for the rapid swings only.

Selection and installation notes

Before ordering a power factor regulator, collect the data the sizing depends on: the supply voltage and frequency, the current transformer ratio and where the transformer is fitted, the number and size of the capacitor steps, the contactor or static switch type and whether harmonics are present on the network. Fit the current transformer upstream of both the load and the capacitor bank so that the regulator sees the net current, connect it with the polarity shown in the manual and let the regulator run its automatic set-up before the first start. Check the alarm and relay settings and write the final values on the commissioning record so that later service work starts from a known state.

Static switching suits loads that change quickly, so check that the capacitor bank and the thyristor or static switch modules are rated together with the regulator.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Related Circutor items

The F6-12Vdc (R13953.) is the 12 Vdc variant. For slower loads, see the computer SMART III 14 (R13864.). The OPTIM SVGm hybrid compensators and AFQs active filter address harmonics and fast response differently.

Frequently asked questions

What does static switching mean for the regulator?

Steps are switched by transistor outputs that drive EMF or EMB static modules, instead of contactor coils.

How fast a load can it follow?

Circutor quotes load variations between 40 ms and 4 seconds.

What is the supply range?

100 to 520 Vac, 50 to 60 Hz.

How many steps are there?

Six.

Is Seven Star LLC a distributor of Circutor?

No. Seven Star LLC supplies Circutor products as an independent company in Muscat, Oman, and does not act as a manufacturer-appointed distributor.

Documents and quotation

This listing carries the computer SMART III Fast 6 datasheet (generated 21/10/2026) for reference. Use it with the manual to confirm the correct order code, then send the code, options and quantity via the quote form. Seven Star LLC works from Muscat as an independent supplier for GCC customers, and prices are provided on request only. Always confirm ratings, options and approvals against the latest manufacturer documents. See Electrical & Power and the Circutor brand page for related items.