DASMA TDS 385 - Opening a Motorized Garage Door During a Power Outage

During a power outage, the garage door opener will not respond to remotes or wall buttons. Many homeowners do not know there is a manual release until they are standing in a dark garage trying to get the car out. DASMA TDS 385 explains the procedure clearly, before you need it.

What this data sheet says

DASMA TDS 385 provides step-by-step instructions for manually releasing a motorized garage door operator and operating the door by hand during a power outage. It also covers re-engaging the operator after power returns and includes important safety warnings.

"The emergency release cord allows the door to be operated manually when the operator has no power. The cord should only be pulled when the door is in the fully closed or fully open position."

The key procedure from TDS 385:

1. Locate the emergency release cord. It is a red rope hanging from the trolley assembly on the center rail. On most residential operators, the cord hangs down from the trolley at roughly the midpoint between the motor head and the door.
2. Pull the cord straight down. Pulling the cord disengages the trolley from the drive mechanism. A click or shift in the trolley confirms disengagement.
3. Lift or lower the door by hand. With the operator disengaged, the door moves freely on its track under spring counterbalance. If the door is properly balanced, it should move easily and remain in place when released at midpoint.
4. Secure the door if you are leaving. An open door with the operator disengaged can be pushed open from outside without a lock. Use the interior lock bar if one is installed, or secure the door in the down position.
5. Re-engage the operator after power returns. Open or close the door to the fully open or fully closed position, then pull the emergency release cord again until it snaps back into engagement. Alternatively, most operators will automatically re-engage when the remote or wall button is used the first time after power is restored.

Critical safety warning from TDS 385: never pull the emergency release cord when the door is in motion. If a spring breaks while the cord is pulled and the door is only held by the cord, the door can fall or move unexpectedly.

When it applies

Power outages that affect garage doors are common across the Front Range for two reasons:

Winter storms. Heavy snow and ice cause utility outages that can last hours or days. An attached garage door that cannot be opened traps vehicles and can become a safety issue if the home needs to be evacuated.

Summer thunderstorms. Colorado's intense summer convective storms produce lightning strikes and wind damage that knock out power to individual homes or neighborhoods. A storm that knocks out power and fells trees simultaneously can make egress through the garage important.

TDS 385 specifically focuses on egress: getting out of the home through the garage in an emergency. The scenario where the occupant is inside and needs to leave is the primary concern. The TDS also addresses the scenario where someone has locked themselves out and needs to get into the garage from outside, though that situation requires access to the interior release cord, which is typically only possible from inside.

What this means for you

Learn the location of the emergency release cord before you need it. Go to your garage right now and find the red rope on the trolley rail. Confirm you can reach it from floor level.

Do not cut or remove the emergency release cord. Some homeowners remove the cord to prevent children from pulling it or to reduce the risk of burglary through the cord release exterior mechanism. This creates a serious egress risk. If burglary is a concern, install a zip tie or lock through the cord to limit its range of motion, not remove it entirely.

Test the manual operation once a year. Disengage the door, lift it manually, and re-engage the operator. This confirms the release mechanism works and gives you practice before a real power outage.

G Brothers services garage doors and operators throughout the Denver metro area and Front Range. If your emergency release mechanism is stiff, broken, or missing, we can restore it.

Full text and source

Download DASMA TDS 385 from the official TDS index at https://www.dasma.com/technical-data-sheets/.

This entry covers emergency manual release for residential garage door operators with ceiling-mounted trolley systems. Jackshaft operators have a different release mechanism described in the specific operator's installation manual.