FAAC 770N vs. FAAC 390
One hides under the hinge. The other bolts to the pillar. The site decides.
The FAAC 770N and FAAC 390 both automate swing gates, but they mount in opposite ways. The 770N is an underground operator in a foundation box beneath the hinge, so nothing shows above ground. The 390 is an articulated arm that bolts to the face of the pillar. The right one depends on the pillars, the drainage, the weight of the leaf and whether the gate has to look untouched.
01The short answer
- Choose the 770N when the gate must look untouched and the ground drains well. It sits in a foundation box below the hinge, and FAAC calls for a drain tube to carry rainwater out of the box.
- Choose the 390 when the pillars are large and the leaf is within its US rating of 14 ft and 600 lb. It bolts to the pillar, has battery backup built in, and stays above ground where it is easy to reach.
- Avoid underground where water collects, where planting will keep packing the box with debris, or where original pillars and gate leaves cannot be modified to take the box.
02Side by side
From FAAC's 770N installation manual and product literature, and the FAAC 390 US manual and specification sheet.
03How the 770N works
The 770N sits in a supporting box set into the ground below the gate's hinge, and the leaf rides on a support frame driven by the operator, so FAAC keeps only the upper hinge. Because the motor is below grade, FAAC calls for a tube to drain rainwater from the box, and for mechanical stops at the open and closed positions.
It is self-locking, and a key release lets you move the leaf by hand from inside or outside the property. When it needs service, the operator can be reached without taking the leaf off.
04How the 390 works
The 390 is an irreversible electromechanical motor with an articulated arm. Its base plate bolts level to the pillar, and FAAC describes it as ideal for large columns. How far the plate sits from the hinge decides whether the arm can reach 90° or 120°, and FAAC publishes tables of the allowed dimensions for gates that open inward and outward.
The US version runs a 24V DC motor from a board on a 115V supply, with two 12V batteries under the backplate. A switch on the board can open the gate a minute after a power failure and hold it open. FAAC's US documents also recommend an added lock where real security is needed or the leaf is long; the manual and the specification sheet give different lengths, so we check your leaf against both.
05Where each one goes wrong
The 770N's weak point is its box. A blocked or missing drain lets water stand around the operator, and in our experience soil, roots or leaves packed into the box are the other common cause, which is why heavy planting near the hinge counts against underground. The 390's faults are easier to read: its E024U board flashes a count that identifies the error condition, and the board, batteries, release and arm can each be replaced on their own.
06From our work
We recently consulted on a historic home with original iron gates and masonry pillars, where the general contractor had specified 770N underground operators. Setting the foundation boxes would have meant modifying the original pillars and gate leaves, and heavy planting along the drive would keep packing the boxes with debris. We recommended a surface-mounted swing operator instead, which kept the original gates intact and every part reachable for service.
07Repair pages for these operators
08Questions buyers ask
Is the FAAC 770N or the 390 better for a heavy gate?
Check the leaf against each rating. The US 390 is rated to 600 lb and 14 ft. FAAC's literature gives the 770N up to 500 kg, about 1,100 lb, with the allowed length set by the opening angle. A leaf beyond either needs an operator sized for it.
Does the FAAC 770N have battery backup?
FAAC's 770N literature lists no battery option. The US 390 has two 12V batteries built in, and its board can open the gate a minute after a power failure. If the gate has to work through outages, that difference matters.
Can a FAAC 770N be replaced with a 390?
Often, yes, if the pillars can take the 390's base plate within FAAC's mounting dimensions and the leaf is within its rating. The hinges need checking too, because a 770N installation keeps only the upper hinge and the 390 needs the gate hung on sound hinges.
Which is easier to maintain, the 770N or the 390?
The 390, in most cases. It is above ground, and its board reports faults by flash count. The 770N can be serviced without removing the leaf, but its box has to be kept drained, and in our experience clear of debris.
Who repairs FAAC 770N and 390 gate operators near me?
Veritas Access Solutions installs and repairs FAAC 770N and 390 operators across Los Angeles, Ventura and Kern counties, including gates another company installed. We give you a written diagnosis before any work. Call 661-605-3266, or text a photo of the operator and we call back within 30 minutes during business hours.
09Sources
Specifications and requirements in this guide come from these documents. Check your own operator's manual before relying on a figure, because ratings change between versions.