Underground or In-Ground Gate operators (for example: MIGHTY MULE 500 ) are the top of the line when it comes to aesthetics and refinement for an estate gate. They consist of steel boxes that are set into concrete at the base of the column or post and attach directly to the bottom of the gate. The circuit board and controls are hidden in a separate box which can be inset into the column or mounted nearby. Because of the low profile these are the ideal choice for doing high end custom gates where the appearance of the finished product is the most important aspect of the install. Due to the way these units connect to the bottom of the gate, it is advisable for installations where there is not more than 3 inches difference in side to side elevation of grade on driveway.
That being said, there are a number of downsides to using this type of operator. First and foremost, you will need to provide drainage for the operator itself since it is mounted below grade. The unit itself will need to be aligned perfectly with the center pivot point of your hinges so that the hinge does not bind up. The initial cost of the operators tends to be the highest of all the styles available. Warranties are typically short with the longest one being 4 years and maintenance can sometimes be a pain depending on the configuration of the operator and the gate.
Mechanical In-ground Operators:
These operators are generally 24VDC. You can find this same unit with several types of electronics driving it. The Platinum Access UGP712 is typical of the 24VDC driven units available and can be powered by 110VAC/220VAC or 24VDC Solar. They include a 4 Year warranty which is the longest on the market and can handle a gate up to 700 lbs and 12’. Viking Access and DoorKing offer similar models, although the warranties are shorter and the DoorKing has a lighter duty weight rating.
Hydraulic in-ground Operators:
FAAC is the lead manufacturer in this field. There are two types of in-ground hydraulic operators. The most common has the pump and dual acting hydraulic piston in the same enclosure. The other version has the pump out-boarded in a cabinet. Both styles use a hydraulic lock to release the gate during an equipment failure. Hydraulic operators need positive stops because they do not have limit switches to control the position. Instead they use a timer on the pump to turn it on and off. Typically you can hear the motor running for a few seconds after the gate has closed or opened. Most of these units run on 110VAC or 220VAC but FAAC recently released the S800Hwhich runs on 24VDC with battery backup and a built-in magnetic encoder to control positioning of the gate. This is a great choice for this type of install because of the high capacity rating at 13’ and 1760 lbs, the nicest features of the available units, and FAAC is a reputable company that stands behind its product.