Littelfuse M-750 Serie Instrucciones De Instalación

Installation Instructions
M-750 Series Battery Selector and Disconnect Switches
Part Numbers: M-750 and M-754
Ordering Information
PART
NUMBER
M-750 Battery Selector and Disconnect Switch
M-754 Battery Selector and Disconnect Switch with Pilot Light Circuit
Mounting
M-750 series switches can be mounted flush or from behind,
through a circular hole. When mounted flush, the switch
covers over any holes previously made. When mounted from
behind, No. 563 self-adhesive plastic sticker is available,
which is identical to the ring-shaped sticker already on the
switch.
Mounting Diagram #1
B2 CL
B1
WARNINGS
Engines must be stopped before the switch is turned to Off. Otherwise the alternator diode might fail.
Refer to the vehicle service manual for the correct method to interrupt the alternator field circuit with an external regulator.
Alternators with an internal regulator cannot be wired with this feature.
Important: Cable connections to terminal 1 and terminal 2 must be of the same polarity. Maximum torque for tightening the hex
nuts on the three terminal studs is 90 inch lbs.
M-750 series switches are specially designed for battery selection and battery disconnect only. They are not recommended for
switching heavy electrical loads.
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DESCRIPTION
CL
A2
A1
Specifications Overview
Intermittent Duty Rating:
Continuous Duty Rating:
Housing:
Voltage Rating:
Terminal Studs:
Installation
Assemble the battery selector in the following sequence:
1. Turn off all circuit power before installing the switch.
2. Install the switch in a safe and dry location near the
batteries in order to keep the battery cable length as
short as possible, in order to reduce voltage loss.
3. For applications requiring maximum current rating (up to
310A continuous, 500A intermittent) use 300AWG (KCM)
size copper conductor cable or larger with at least 105ºC
rated insulation.
Please Note: Panel mounting may be necessary. to provide
space for large cables.
For applications using cable smaller than 300AWG, the
maximum continuous current rating of the circuit must be
de-rated accordingly
4. Verify that the terminal temperature does not exceed
100ºC
Additional Notes: Make-before break contact design permits
selection of Battery 1 or Battery 2 or both batteries in parallel,
with engine or engines running.
Off position disconnects the battery circuit only.
Surface Mounting
Drill four holes on a 5.500" diameter circle (139.7mm). Hole
size 0.218" (5.53mm) diameter will accept No.10 screws.
A1 = 1.944" (49.38mm)
A2 = 3.888" (97 .78mm)
CL = Center line
Through Panel Mounting
Housing & knob clearance hole 3.312" diameter (84.12mm).
Drill four holes on a 4.395" diameter circle (116.63mm). Hole
size 0.201" (5.10mm) diameter, 0.5" (12.70mm) deep for 1/4"
-20 bolts.
B1 = 1.553" (39.46mm)
B2 = 3.107" (78.92mm)
CL = Center line
1 of 4
500A at 12V DC
310A at 12V DC
Nylon UL 94-V0
6-36V DC
3/8' Diameter (9.53mm)
IF-63-5 Rev: 010320-C