Murphy MTH6 Installation And Operation Instructions

Model MTH6 Tach/Hourmeter Overspeed Switch
Installation and Operation Instructions
Please read the following information before installing. A visual inspection of this product for damage during shipping is recommended
before mounting. It is your responsibility to have a qualified person install this unit.
WARNING
BEFORE BEGINNING INSTALLATION OF THIS MURPHY PRODUCT
✔ ✔
Disconnect all electrical power to the machine.
✔ ✔
Make sure the machine cannot operate during installation.
✔ ✔
Follow all safety warnings of the machine manufacturer.
✔ ✔
Read and follow all installation instructions.
Description
Microprocessor-based digital tachometer and hourmeter with a built-in
overspeed switch. This Murphy instrument is highly accurate and depend-
able. It measures speed and running hours and can give an alarm or shut
down the engine on overspeed.
RPM data for the tachometer and overspeed switch is supplied by a mag-
netic pickup or a battery charging alternator equipped with a "Tach" termi-
nal (auxiliary AC terminal). The magnetic pickup is installed into the fly-
wheel housing of an internal combustion engine, so that the starter ring gear
acts upon it to generate a voltage pulse each time a gear tooth passes the end
of the magnetic pickup.

Specifications

Power Requirements: 8-40 VDC (12, 24 or 32 VDC system).
Maximum Current:
12 VDC: 0.011 A, backlight Off; 0.025 A, backlight On.
24 VDC: 0.008 A, backlight Off; 0. 015 A, backlight On.
32 VDC: 0.007 A, backlight Off; 0. 010 A, backlight On.
Operating Temperature: -4° to 158°F (-20° to 70°C).
Storage Temperature: -40° to 185°F (-40° to 85°C).
Case: 1018 Polycarbonate/Polyester blend.
Speed Input: 4.5 Vrms minimum.
Input Frequency Range: 25 Hz to 20 kHz.
Overspeed Switch Rating: 2 A, 50 VDC.
Overspeed Range: 0 to 9000 kHz.
Pulses per Revolution: 4 to 255.
Tachometer Range: 0 to 65,535 RPM.
Tachometer Accuracy: ±1% of display reading,
or -2 RPM whichever is greater.
Hourmeter Range: 0 to 99999 hrs.
Hourmeter Resolution: ±0.1 hour to 9999.9; ±1 hour 10,000 and up.
Reset Hourmeter: Ground terminal #5 to reset hours to zero.
Shipping Weight: 14 oz. (435 g).
Shipping Dimensions: 5-1/2 x 5-1/2 x 5-1/2 in. (140 x 140 x 140 mm).

GENERAL INFORMATION

3-33/64 in.
(89 mm)
Diameter
MTH6 Mounting Schematic
To mount the MTH6 to your panel, a 3-3/8 in. (86 mm) diameter mount-
ing hole is required. Remove the mounting bracket and lock nuts (provid-
ed with the unit).
Insert the MTH6 module from the front of the panel, see schematic below.
Replace mounting bracket and secure in place with the lock nuts.
MTH6 Module
MTH-96116N page 1 of 2
Dimensions
Side View
3-1/8 in.
15/32 in.
(79 mm)
(12 mm)
Mounting
Bracket
3-5/8 in.
(92 mm)
Diameter
Mounting Hole
3-3/8 in.
(86 mm) Dia.
Mounting Hole
Panel
MTH-96116N
Revised 04-05
Section 20
(00-02-0778)
Front View
®
FRANK W.
MFR.
MTH6
SETPOINT
ENTER
Back View
3-9/16 in.
(90 mm)
®
FRANK W.
MFR.
5
Mounting
Bracket
Nuts to
Secure
Mounting
(provided)