Cummins Automatic Voltage Regulators
A Cummins AVR is the small control board inside your alternator that keeps voltage steady while the load changes. Cummins Generator Technologies builds the STAMFORD and AVK alternators found on many Cummins generator sets, so the regulators we carry bear those names. At General Power, we have supplied these parts from Miami, Florida since 1999 as an original equipment manufacturer, master distributor, and authorized dealer.
How a AVR Keeps Generator Voltage Steady
The regulator reads the voltage leaving the alternator and compares it to a set target. When a large load comes on and voltage starts to sag, the AVR sends more current to the exciter field to bring it back up. When load drops off, it does the opposite.
This happens many times each second, so lights do not flicker and sensitive electronics stay safe. It works the same way whether the regulator sits inside one of our Cummins powered diesel generators or a standalone STAMFORD alternator paired with another engine.
Cummins Automatic Voltage Regulators Matched to Your Excitation System
The biggest factor in choosing a regulator is how your alternator powers it. Self excited machines feed the AVR from the main stator windings. Machines with a permanent magnet generator, or PMG, give the AVR its own separate power source. The models below cover both designs.
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SX460: a compact self excited unit for smaller alternators in basic standby service.
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SX440: a self excited unit with tighter regulation and connections for paralleling accessories.
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AS440: a newer self excited design that replaces the SX440 on many current alternators.
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MX341: a PMG powered unit that holds voltage well during motor starting.
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MX321: a PMG powered unit with three phase sensing and added protection for demanding sites.
If your alternator has a permanent magnet generator mounted on the end opposite the engine, you need an MX type regulator. We also stock the digital DM110 and the MA330 for AVK machines. Our wider range of voltage regulators for other alternator makes is available if your set uses a different brand.
Details to Confirm Before You Order a Cummins AVR
A regulator that looks alike on the outside may be wired very differently. A few minutes spent gathering details from your machine prevents a wrong order and extra downtime. Have this information ready when you contact us.
- The part number printed on the label of your current AVR
- The alternator model and frame size shown on the nameplate
- Whether the alternator is self excited or uses a PMG
- The sensing voltage and whether the set runs at 50 Hz or 60 Hz
- Whether the generator runs in parallel with other sets
Common signs of a failing regulator include voltage that swings up and down, no output at all, or voltage that climbs too high. Worn diodes can cause similar symptoms, so it is smart to inspect the rectifier assembly at the same time. Replacing both together often saves a second service visit.
Why Buyers Choose General Power
Our sales specialists and engineers are each certified by the Electrical Generating Systems Association and can match a regulator to your alternator before you buy. Our bilingual staff offers same day quoting and shipping with full after sales support.
We have served over 10,000 customers in more than 100 countries and earned an A+ BBB rating. We also supply generator control panels and transfer switches. Request a quote today for the right Cummins AVR.
