Simpson Electric Mini-Max M245 Series Operation Manual

Mini-Max M245 Series Digital Panel Meter

Minimum Depth Indicator - Less Than 2.5” (60mm) of
Space Required Behind the Panel

Stackable Mounting Bracket Included for
Easy Installation

LCD: 4-1/2 Digit, 0.5” (12.7mm) High LCD Display with
Optional Negative Image, Bright Red Backlighting

LED: 4-1/2 Digit, 0.4” (10.2mm) High Display

Limited Range Display Scaling

Standard Screw Terminals for Easy Installation

Six Current Ranges: 200µA, 2mA, 20mA, 200mA, 2A, 5A

85-250VAC or optional 9-32VDC Power Supply

DC Current

LCD

LED

Simpson’s Mini-Max Voltage Indicators provide high quality,
accuracy and reliability in a compact, 60mm deep case.

LCD (Liquid Crystal Display) Units oer a 4-1/2 digit, 0.5”
(12.7mm) LCD display with an optional bright red, negative
image, backlight.

LED (Light Emitting Diode) Units oer a 4 1/2 digit, 0.4”
(10.2mm) Display.

Installation and Panel Cutout

2.68” (68mm)

0.88" (22.2mm)

2.68"

(68mm)

All units feature user-selectable decimal point, auto zero and
limited scaling capabilities.

A unique mounting bracket is provided to allow for vertical
or horizontal stacking of multiple indicators. All Mini-Max
units feature a 3/64 DIN, high-impact plastic case. The
LCD units have a clear viewing window, and the LED units
have a red viewing window.

2.84" (72mm)

0.95"

(24mm)

0.16"

(4mm)

2.36" (60mm)

0.13" (3.18mm) Max
Panel Thickness

0.874"
(22.2mm)

Mounting Requirements

Insert the Mini-Max through the panel, and then slide the mounting bracket
onto the Mini-Max. The mounting bracket allows Mini-Max units to be
stacked side-to-side or top-to-bottom and maintain the DIN standard
panel arrangements in 24mm by 72mm multiples. Panel cutout instruc­tions for stacking multiple units are provided under “Stacking Features.”

DISPLAY
Type: 7-segment LCD or LED
Height:LCD 0.5” (12.7mm)

LED 0.4” (10.2mm)

Decimal point:4-position selectable

Overrange indication:

LCD Most signicant digit = “1”
LED Blinking display

LCD Backlighting: Optional negative image, red

Polarity: Auto with “-” indication, “+” implied

POWER REQUIREMENTS
AC Volt: 85-250VAC @40-440Hz
DC Volt: 9-32VDC

Power Consumption: (Non Fused)

85-250VAC: LCD 4.0VA (2.4W) max

9-32VDC: LCD 3W max

Isolation: 250Vrms

DCA

LED backlighting

LED 3.6VA (2.16W) max

LED 2W max

LCD

NOISE REJECTION

CMRR: 86dB typical

ACCURACY @ 25°C

±(0.04% of reading ± 1 count)

2A: ±(0.25% of reading ± 1 count
5A: ±(0.5% of reading ± 1 count)

ENVIRONMENTAL
Operating Temperature:0 to 55°C
Storage Temperature:-10 to 60°C
Relative Humidity: 0 to 85% non condensing

@ 40°C

Temperature Coecient:

(0.2% of input ± 0.5 digits)/°C
Warmup time: Less than 20 minutes

ANALOG TO DIGITAL CONVERSION
Technique:Integrating dual slope
Rate: 3 samples/second-typical

LCD

LED

Range Resolution Voltage Max Input Voltage Max Input

M245

Drop Unfused Drop Unfused

200uA 10nA 200mVdc 10mA 200mVdc 6mA

2mA

100nA 200mVdc 40mA 200mVdc 20mA

20mA

1uA 200mVdc 100mA 200mVdc 60mA

200mA 10uA 200mVdc 400mA 200mVdc 300mA

2A 100uA 200mVdc

5A 1mA 50mVdc

3A 200mVdc 2.6A

6A 100mVdc

LED

6A

MECHANICAL
Bezel: 0.95” x 2.84” (24mm x 72mm)
Depth:2.36” (60mm)
Panel cutout: 0.88” x 2.68”

Weight: LCD 3.5oz (99.2g)

Case Material:

94-0,UL-rated, glass-lled thermoplastic

INPUTS: DC Current

(22.2mm x 68mm)

LED 2.6oz (74g)

DP4 DP3 DP2 DP1

Connections

LCD VERSIONS

POWER

IN HI+

IN LO-

INPUT SIGNAL

DP3

DP1

DP2

DP4/

HOLDDPCOMMON

WARNING: These instruments are designed for maximum safety to the operator when mounted in a panel according to

instructions. They are not to be used unmounted or for exploratory measurements in unknown circuits.

POS

EXCITATION

OUT

NEG

-DC

AC LINE

+DC

Input Signal: Connect the DC sig nal to be monitored to the IN HI+ and IN LO- input terminals.

Input Power: For AC power, connect the AC POWER LINE to the AC LINE inputs. For optional DC power, connect the DC Supply to

the DC inputs. Observe polarity.

Decimal Point: To select a decimal point, connect the appropriate DP input pin (DP1 - DP4) to the DP COMMON output. Unused DP inputs

may remain unconnected (open).

Connect the DP COMMON output to the HOLD input. If this feature is not required, the HOLD pin may remain unconnected.LCD Hold Option:

Hold is optional on LCD versions only, replaces DP4 and is available from our modication center.

IN HI+

NOT

USED

INPUT SIGNAL

IN LO-

DP3

LED VERSIONS

DP2

DP1

DP4

DP

COMMON

POS

EXCITATION

NEG

OUT

POWER

-DC

AC LINE

+DC

LCD Backlight
Option:

Negative image, bright red backlighting is available for the LCD versions only. This illumination allows the unit to be read in low
light areas. Backlighting power is supplied by the Mini-Max, so no additional external power is required.

Excitation Option: Excitation is available at the EXCITATION OUT Positive (POS) and Negative (NEG) terminals for powering external transmitters

or transducers. This source is isolated from the measurement input as well as the input power circuits. The voltages available
are 12Vdc or 24Vdc with a maximum load current of 25mA. This feature eliminates the need to mount an external DC power
source for transducers or sensors used in your application.