Main Drain Suction Hazards

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In recent years, accidents involving swimming pool and spa main drain suction have pointed to the need of a means of protecting swimmer safety. Suction pressures in main drains caused by recirculating or hydrotherapy jet pumps can be so strong as to disembowel or entrap the swimmer. In an effort to minimize this hazard, the Ohio Swimming Pool Rules now require that certain safety measures be put into place in shallow bodies of water where contact with the main drain is more likely. This applies to all spas, all wading pools, and any special use pool 36 inches or shallower in depth.

For the most part, there are two acceptable options for the pool operator. If spacing permits, a second main drain can be added to the pool or spa, thereby splitting the suction pressure between two drains and reducing the suction to an individual main drain. This also provides another path for suction should one of the main drains temporarily become inoperative. This would be the preferred method since there are no mechanical devices to fail or that require routine testing in the future. Another option is the installation of a device called a Vacuum Limit Switch. This device senses a blockage on the drain and immediately shuts down the pump. One of these options must be applied to each pump in a pool or spa having only one main drain on direct suction.

The Ohio Department of Health has recognized two vacuum limit switches for this application. The manufacturers and contact information are as follows:

Stingl Switch
Mike LowSpa Parts Plus
7175 E. Second Street
Prescott Valley, AZ 86314
Phone 1-800-521-7587 ext. 122
Fax 1-800-366-7727
email mikel@spaparts.com www.stingl-switch.com

Vac-Alert Device Vac-Alert of Ohio
Dave Bachman
6809 Main Street
Newtown, OH 45244
Phone 877-644-6822 (toll free)
Fax 513-561-6870
www.vac-alert.com