Viking Model EA-1 Electronic Accelerator for Dry Systems

A quick-opening device that watches system air pressure

The Viking Model EA-1 is an electronic accelerator for select Viking double interlock preaction systems with electric or Pneu-Lectric release and for select dry pipe systems. It speeds up valve operation by monitoring air or nitrogen pressure twice a second through an internal pressure transducer. If it sees a severe drop, greater than 0.1 psi (0.007 bar) per second over three consecutive samples, it signals the VFR-500 release control panel. Viking states the accelerator operates the preaction or dry pipe system within four seconds and also serves as the air supervisory switch, with low and high pressure supervisory alarms.

Part number 27327 is the EA-1 on its own; other options and configurations are described in section 7 of the data sheet.

Technical specifications

Rotary switch settings set the low and high air pressure thresholds for each system, and the data sheet includes a table for the VXR pressure settings.

Where it fits in the system

On a dry pipe system, the accelerator directs its solenoid outlet air to the intermediate chamber of the Viking VXR or Model F dry valve. As air pressure rises there, the differential is overcome and the valve opens. On a double interlock preaction system, the detection circuit sets off the alarm first and a sprinkler operating then triggers the accelerator, which activates the control panel second circuit. Both circuits must be active before the panel opens the solenoid valve.

The accelerator needs a solenoid valve and works together with the panel. Radio transmitters and RF sources must be kept at least one foot from the unit, and shielded wire can be used to guard against accidental activation.

The EA-1 is wired as an initiating device to the VFR-500 panel and carries rotary switch pressure settings for the low and high air thresholds. The standby draw of 68 mA at 24 Vdc and the 5 mA contact rating should be checked against the panel supply and circuit design, and Viking points to section 8.3 of the data sheet for the VXR pressure settings. Maximum rated air or nitrogen pressure is 70 psi (4.8 bar).

Important limit stated by Viking

Viking states that accelerator activation does not guarantee that the water delivery time required by the authority will be met. Delivery time is determined mainly by the piping layout and volume, the system air or nitrogen pressure at activation, the number and orifice size of operating sprinklers and the water supply characteristics, so the designer must run the delivery time calculation. Compare the Model D-2 and E-1 accelerators listed on the F-1 dry valve page, and see our Fire Fighting equipment.

Confirm before ordering

Confirm the valve model, system volume against the 2,250 gal limit, release control panel, solenoid valve, rotary switch settings and electrical supply. The attached Viking data sheet runs to 25 pages and includes wiring and commissioning information. Send the system details and quantity for a quotation.