Manufactured by:Veethree Instruments 2420 Trailmate Dr. Sarasota, FL 34243 Phone (941) 538-7775 FAX (941) 755-1222www.v3instruments.com

Mechanical Tachometerwith HourmeterINSTRUCTIONS

FOLLOWING ARE INSTRUCTIONS FORINSTALLING AND WIRING THEMECHANCAL TACHOMETER/HOURMETER.

CAUTIONREAD THESE INSTRUCTIONS THOR-OUGHLY BEFORE PROCEEDING WITHINSTALLATION. DO NOT DEVIATE.

Additional materials required to completeinstallation:Tachometer Cable Assembly If lighting is desired,

No. 16 stranded insulated wireInsulated terminal lugs as required5/8” light socket and bulb.

PREPARATION FOR INSTALLATION1. Select a mounting location for gauge whichprovides for easy readability from theoperating position. Check behind panel forsufficient installation clearance .2. Cut a 3-13/32 (86mm) diameter holethrough panel at desired location.3. Insert Gauge into mounting hole in paneland check for fit.

4. Open Hardware Package. Fit “U” bracketover mounting studs on back of gauge (SeeFigure 1). NOTE: Legs of bracket may beshortened if needed to accommodate thickerpanels.

INSTALLATION OF GAUGEAfter checking fit of gauge and “U” bracket,insert Gauge into panel and install bracketover mounting studs. Install a nut and washeronto each mounting stud as shown in Figure1. CAUTION: OVERTORQUING OF NUTSMAY CRACK GAUGE HOUSING ORMOUNTING PANEL.

INSTALLATION OF CABLE1. This Tachometer accepts a flexible drivecable with a .104” square drive tip and issecured with a 5/8” - 18 NF - 3A threaded nut.2. After installing the gauge, insert the squarecable tip into the gauge and tighten the nutfirmly by hand. A pliers may be used to finishtightening the nut. Do not overtighten.

INSTALLATION OF OPTIONAL LIGHTING1. Remove plastic plug from socket hole.2. Snap lamp and socket into socket hole.3. Connect wires as shown in Figure 2.

HOURMETER INTERPRETATIONThe Hourmeter Counter actually reads enginerevolutions in hundreds of thousands ofrevolutions. At a specific RPM the counterfunctions as an hour indicator. If your normalcontinuous RPM is not shown in the followingchart, use the formula to determine averageengine hours at your normal operating RPM.Tachometer may be other than 1:1 drive ratio(reads cable speed). Also, various counterdrive ratios are used.Cable Ratio Hourmeter Hourmeter is

Ratio Accurate atIndicated RPM:

.5 : 1 375 : 1 1250

.5 : 1 495 : 1 1650

.5 : 1 550 : 1 1833

.875 : 1 630 : 1 1200

.35 : 1 495 : 1 23571 : 1 1000 : 1 16671 : 1 1260 : 1 2100

Formula for time at other RPM settings:1. RPM (from table above) divided by averagecontinuous RPM.2. Multiply result by Hourmeter Reading.3. This is the actual operating time at theaverage continuous RPM setting.

4. Example:

1 : 1 Drive Ratio, 1000:1 Hourmeter Ratio -Accurate RPM = 1667Average Operating Speed: 1850 RPMHourmeter Reading: 500 hours

1667 = .90 .90 x 500 Hours = 450.41850 Actual Hours

P.T.O. LABEL1. Some Tachometers have P.T.O. revolutionsmarked on the dial. For this reason, a P.T.Odecal may be enclosed.2. Place the decal on the glass as indicated bythe dial markings of the previous tach.

S015 Rev. 5