Marshall Excelsior Accu-Max+ Series Service manual

ACCU-MAX+ SERIES
Marshall Excelsior Company Base Engineering
1506 George Brown Drive Marshall, MI 49068 600 Rothesay Ave, Saint John, NB E2H 2H1, Canada
Phone [phone] Fax [phone] Phone [phone] Fax [phone]
www.marshallexcelsior.com www.baseng.com
The contents of this publication are for informational purposes only. While every effort has been made to ensure accuracy, these contents are not to be construed as warranties or
guarantees, expressed or implied, regarding the products or services described herein or for their use or applicability. Marshall Excelsior Co. and BASE Engineering reserve the right to
modify or improve the designs or specifications of such products at any time without notice. The MEC™/BASE™ logo is the trademark of Marshall Excelsior Co. and BASE Engineering.
FORM #1173 1 REV B 7/13/2021
Installation Information
1Before you Begin & Qualified Installer Requirements
BEFORE YOU BEGIN
•Carefully read this Installation Guide before installing this
product. If anything is unclear, please contact BASE
Engineering for support.
•Ensure that the NEGATIVE battery connection is disconnected
before beginning work.
NOTE: Some components may lose short-term memory (i.e. engine or
transmission adaptive parameters and radio presets) after a prolonged time without battery power.
•Accu-Max+ should be serviced by qualified, trained personnel only. Attempting to remove the
cover or disassemble the device could expose you to dangerous high voltage points.
•Do not attempt to install or operate a damaged device. If the unit has been exposed to excessive
amounts of water, shows evidence of physical damage, or is not operating properly, unplug it
from the power source and contact qualified service personnel.
•Use of thread-locking compounds, such as Loctite, may cause serious damage to plastic
enclosures. Many thread-locking compounds are not compatible with thermoplastics and can lead
to stress-cracking.

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FORM #1173 2 REV B 7/13/2021
QUALIFIED INSTALLER
This product is to be installed by qualified
installation personnel only.
The installer must be trained in industry best-
practices for this type of installation. The
training would include but not be limited to:
1. The appropriate methods for installing cables such that:
•The operation of the vehicle is not interfered with.
•The installation process does not damage or interfere with other vehicle components and/or
systems.
•Wiring is kept clear of sharp objects, sources of heat and any other hazard that could damage the
cable or wire.
•Wiring is secured such that it does not cause damage to other equipment or itself, nor interfere with
the operation of other systems and devices.
•Wiring through bulkheads is performed such that wiring does not chafe, and a seal is maintained
between compartments.
•Appropriate, industry standard fasteners, splices, connectors and ties are used for the vehicle
environment.
•Appropriate slack is in place to prevent straining of the wire, cable or connectors.
•Any other issue that could affect the integrity of the wiring or the safe operation of the vehicle is
addressed appropriately.
2. The appropriate methods for mounting equipment in vehicles such that:
•The safe operation of the vehicle is not interfered with.
•The equipment is attached to the vehicle as securely as possible to minimize the risk of the
equipment breaking free in an accident situation.
•The installed device does not interfere with the deployment of air bags.
•The installed device does not obscure displays or interfere with the ability of the driver to operate
other vehicle systems and components.
•The installation process does not damage other vehicle systems or components.
•Compartments remain sealed against the elements.

ACCU-MAX+ SERIES
FORM #1173 3 REV B 7/13/2021
3. The correct use and operation of the required tools such that:
•The installer must have the ability to read, understand and follow the instructions in the installation
manual.
•The installer must be equipped with the correct tools for performing each installation operation.
The customer must ensure that the installation of all equipment provided for this project is safe, used for
its intended purpose, and is in continual accordance with all applicable codes, rules, regulations and
guidelines provided by motor vehicle and equipment manufacturers, as well as any state, local or
jurisdictional bodies.

ACCU-MAX+ SERIES
FORM #1173 4 REV B 7/13/2021
2System Components
Accu-Max+ System includes the following key components:
1. Digital Dial
2. Barrier
3. Harness
4. Optional Brake Pressure Switch
Figure 2-1 - Accu-Max+System Drawing (Not to Scale)
Black
GND
Red
+12/24VDC
To PC3 Receiver or OBC
To Battery
through a 2A Fuse
BARRIER
DIGITAL DIAL
COM
N /O
Gray
Connector
Black
Connector
Brake Pressure Switch
(optional)

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FORM #1173 5 REV B 7/13/2021
3Installation
•If the digital dial is used without activating the tilt compensation feature, it may be located in any of
the 6 standard positions shown in Figure 2, including the default “End Mount” identified as Position
1.
•In order to enable the tilt compensation feature, the dial must be configured with the tank
dimension parameters, float dimension parameters, as well as the Installation position.
oThe tilt compensation will only valid in the specified Position and cannot be relocated
without reconfiguring the dial.
oThe estimated volume display will be automatically enabled when the tilt function is
configured.
•The estimated volume field may be enabled without the tilt compensation if the float dimensions
are not provided.
Figure 3-1 – Typical Installation Locations of Digital Dial
•Barrier is mounted inside the truck cab.
oOn transport trailers, the potted version of barrier may be installed exterior to the truck cab.
In this case, ensure power is disconnected from the barrier while loading. This unit is not
rated for hazardous locations.
•The cable with Black Deutsch connector is used to connect Barrier to Digital Dial and Break Pressure
Switch (using the Break Pressure Switch is optional).
•The cable with Gray Deutsch connector is used to power up the Accu-Max+ system. To power up the
system, locate the Red and Black wires and connect them directly to truck battery FUSED (2A fuse)
and negative terminals. This cable also contains a separate RS485 communication port.

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FORM #1173 6 REV B 7/13/2021
4System operation
4.1 Digital Dial
4.2 BASE Engineering External Safety Barrier
The external safety barrier has 2 LED indicators and they are labeled as POWER and ACTIVITY.
•POWER LED is solid Blue when the system is ON, otherwise it is OFF.
•Activity LED:
oIf no remote host (e.g. BASE Receiver Module) is connected to Barrier, Activity LED is OFF.
oIf a remote host (e.g. BASE Receiver Module) is connected to Barrier (to communicate to a
PC3 Receiver or an OBC, connect serial port to compatible RS485 port):
Activity LED blinks in Blue color when the system has normal communication
between Digital Dial and PC3 Receiver or OBC.
Activity LED blinks in Red color indicates that the PC3 Receiver or OBC is
communicating on the line, however the Dial may not have responded.
Fill level as a percent
Tilt compensation is
active when lit
Product volume estimate
Note: Only valid when tank
dimensions are calibrated properly
Dial harness connector
Mounting holeMounting hole
Fill level bar graph

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FORM #1173 7 REV B 7/13/2021
5Operational Specification
•Power Supply: 12V / 24V (Absolute Range 9V – 32V)
•Nighttime Backlit Current Draw: 90mA @ 12V
•External Fuse Rating: 2A
•Communication Link:MODBUS over RS485 at 9600 Baud
•Operating Temperature Range: -40°C to +50°C
•Fill Limits: Selectable 5-95% or 3-97%

ACCU-MAX+ SERIES
FORM #1173 8 REV B 7/13/2021
6Mechanical Specification
5.22"
4.625"
4.02"
4.65"
2.95"
4.73"
Ø0.315"
Length: variable
Length: 15'
Length: 15'
Length: 3'
Black
Red
Gray
Connector
Black
Connector
COM
N/O
3/8" NPT
0.827"
1.968"
Black
Red
Length: 1.5'

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FORM #1173 9 REV B 7/13/2021
7Dial Configuration
The basic “out-of-the-box” configuration of the Accu-Max+ digital dial can only provide a reading of the
percentage fill of product within the tank. In order to enable the volume and tilt compensation, the dial
must be loaded with all key details of the tank, including dimensions, float arm measurements and precise
location of the dial.
Much of the required information is available on the Tank Plate (i.e. tank radius/diameter, length and
shape), and several typical preset locations are available to aid in the configuration process. Additionally,
the float arm dimension is required, along with any offset (into or out of the tank) in the mounting of the
arm to be able to locate where the pivot point is of the arm within the tank (the key dimension needed in
this case is any tank offset and the Flange-to-Pivot Length).

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Figure 7-1: Float Arm Mounting - Pivot Point and Proud/Recess Mount
Use the table below to help gather all required information:
Table 7-1: Dial Configuration Worksheet
Parameter
Value
Notes
Tank Length, inches
Outer dimension. Generally stamped on the tank
plate.
Tank Radius, inches
Outer dimension. Generally stamped on the tank
plate.
Shell Thickness, inches
Generally stamped on the tank plate.
Tank Head Shape
(“Hemisphere”/”Elliptic”)
Generally stamped on the tank plate.
Mounting Point Proud/Recess, inches
See Figure 7-1.
Flange-to-Pivot Length, inches
See Figure 7-1.
Flange-to-Bulb Centre, inches
See Figure 7-1.
Mounting Position, A-G
As defined in Figure 3-1.
Volume Display Enable, Y/N
Volume Units, Gallons/Litres
Tilt Compensation Enabled, Y/N
Backlight Color(Optional)
Select from: Green, Dark Blue, Sky Blue, Red,
Yellow, Orange, Purple, Pink, Teal, Magenta, or
White.
Tank Identifier (Recommended)
Serial Number or unique identifier of tank.

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FORM #1173 11 REV B 7/13/2021
8Troubleshooting
8.1 Barrier Troubleshooting
•Blue Power LED is not illuminated.
oEnsure barrier has power, with a voltage range not exceeding +9V to +32V.
Check for blown 2A fuse and replace it if necessary.
Ensure vehicle is providing power to barrier (verify operating conditions of the
vehicle (e.g. keyed power via ignition, physical disconnection of power connector on
transport, etc.)
•Activity LED is not illuminated.
oThe Activity LED will only be illuminated if data is present on the RS485 bus.
oIf data is present on the bus and the LED is not illuminated, verify the RS485 data cable of
PC3 receiver or OBC is secured to the barrier harness (on the Grey Deustch Connector).
•Activity LED intermittently switches from Blue to Red.
oThis condition can occur during normal operation. Confirm that data is being received by
the PC3 or OBC. If data is not being received, verify the connection between the Barrier and
Digital Dial.
•Activity LED blinks Red without any Blue.
oThis condition indicates that the PC3 or OBC is sending data on the RS485 line, however the
Digital Dial is not responding.
This may be a normal condition if multiple devices share the same data bus.
oIf the Digital Dial is not responding, and it should be:
Verify the connection between the barrier and dial.
Verify that the digital dial is powered on.
•While the digital dial is on, it will display either the fill level or “- -".
8.2 Digital Dial Troubleshooting
•Display is blank
oVerify that power is being supplied to the Digital Dial.
Inspect the Barrier to ensure Power LED is solid Blue.
•If the Barrier Power LED is Blue, verify the connection between the Barrier
and Digital Dial.
•Display is showing a double dash “- -“.
oThis is a normal condition if the optional parking brake has been released or the dial has
been commanded to turn off by optional PC3 or OBC.
Verify if the optional parking brake is engaged.
Verify via the optional PC3 or OBC if the display has been commanded “off”.

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FORM #1173 12 REV B 7/13/2021
Appendix A: Hazardous Location Details
WARNING! When installed in hazardous locations where the dial may be exposed to flammable vapors (e.g.
propane), the dial must be connected via a suitably rated intrinsically safe power supply. The connection of
non-intrinsically safe power and communication could result in fire or explosion of flammable vapor causing
serious injury or death.
Note: The insulation between the Intrinsically Safe Circuit and the body of the digital dial is below 500V rms.
Table A-1: Digital Dial UL Markings and Standards
UL Marking
UL/cUL
Class IZone 1 AEx ib IIB T4 Gb
Ex ib IIB T4 Gb
Temperature Range
-40°C to +50°C
Applicable Standards
UL 60079-0, Seventh Edition
UL 60079-11, Sixth Edition
CAN/CSA C22.2 No. 60079-0, Third Edition
CAN/CSA C22.2 No. 60079-11, Second Edition
UL 508, Eighteenth Edition
CSA C22.2 No 14-18, Thirteenth Edition
Entity Parameters:
Terminal M12 Connector Pins 4 and 5 to be connected to a simple apparatus.
Terminal M12 Connector Pins 1-3,6-8
Parameter
Ui
Ii
Pi
Li
Ci
Group IIB 9.6V 610mA 0.94W 5.17uH
13.42uF
Environmental Ratings:
The relation between ambient temperature and the assigned temperature
class is as follows:
Ambient temperature range
Temperature Class
-40°C ≤ Ta ≤ +50°C
T4
IP rating of 20.

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FORM #1173 13 REV B 7/13/2021
Installation Notes:
1. Selected associated apparatus must be third party listed as providing intrinsically safe circuits for the
application, and have Voc or Vt not exceeding Vmax (or Uo not exceeding Ui), Isc or It not exceeding Imax
(or Io not exceeding Ii), and the Po of the associated apparatus must be less than or equal to the Pmax or Pi
of the intrinsically safe equipment, as shown in Table A-2.
2. Capacitance and inductance of the field wiring from the intrinsically safe equipment to the associated
apparatus shall be calculated and must be included in the system calculations as shown in Table A-2. Cable
capacitance, Ccable, plus intrinsically safe equipment capacitance, Ci, must be less than the marked
capacitance, Ca (or Co), shown on any associated apparatus used. The same applies for inductance (Lcable,
Li and La or Lo, respectively). Where the cable capacitance and inductance per foot are not known, the
following values shall be used: Ccable = 60 pF/ft., Lcable = 0.2 µH/ft.
TABLE A-2:
I.S. Equipment Associated Apparatus
V max (or Ui) ≥Voc or Vt (or Uo)
I max (or Ii) ≥Isc or It (or Io)
P max (or Pi) ≥Po
Ci + Ccable ≤Ca (or Co)
Li + Lcable ≤La (or Lo)
If Po of the associated apparatus is not known, it may be calculated using the formula Po = (Voc * Isc)/4 =
(Uo * Io)/4.
3. Intrinsically safe circuits must be wired and separated in accordance with Article 504.20 of the National
Electrical Code (ANSI/NFPA 70) or other local codes, as applicable.
4. In the United States wiring methods must be in accordance with the National Electrical Code, ANSI/NFPA
70, Article 504. Additional installation information can be found in ANSI/ISA-RP 12.6.
5. In Canada all wiring shall comply with the Canadian Electrical Code Part I and Local Electrical Codes