Texmate, Inc. Tel. (760) 598-9899 • www.texmate.com
Page 2
UM-35ACI Data Sheet (UM03)
Functional Diagram
Connector Pinouts
Component Layout
Signal Conditioning Components
Calibration Procedure
UM-Series are connectable using the TB-KIT screw terminal
blocks provided with the meter. For greatest convenience, order
a Texmate Push-On screw terminal connector. Alternatively, a
pcb edge connector can be used.(see connector options)
Pins 1 & 2 - Display Test: All numeric display segments will light
up when this pin is connected to the H/T Common Pin. A Texmate
TB-KIT Screw Terminal Clip can be used to access the Display Test
function.
Pins 3, 4, C & D - H/T Common Pin: The Hold and Display
Test pins have to be connected to this pin to activate their
respective functions.
Pins A & B - Hold Reading: If this Pin is left unconnected, the
meter will operate in a free-running mode. When this pin is con-
nected to the H/T Common pin, the meter will latch up. A/D con-
versions will continue, but the display will not be updated until
Pins A & B are disconnected from the H/T Common pin. If this
function is to be accessed through a Texmate TB-KIT Screw
Terminal Clip, then jumper J5 will have to be opened to dis-
connect the Test function. If both hold and test functions need
to be accessed, a PCB edge connector (part no. CN-L15)
should be used.
Pins 6, 7, F & H - Signal High Input: Signal High input for the
meter. Two factory installed ranges for direct connection to a 1A
or 5A CT (Current Transformer).
Pins 8, 9, J & K - Signal Low Input: Signal low input of the A/D
Converter.
Pins 11 & M - AC1 - Live AC Power Input:
Pins 12 & N - AC2 - 110/220V AC Power Select:
Pins 13 & P - AC3 - 110/220V AC Power Select:
Pins 14 & R - AC4 - Neutral AC Power Input:
A
1
2
3
4
5
J5
6
7
8
9 10 11 12 13 14 15
B
C
D
E
F
H
K
J
L M N
P R
S
PCB
A
B
C
D
E
TST
H/T
I/P
LO
I/P
HI
1
2
3
4
6
7
8
9
11
12
13
14
A
B
C
D
E
HLD
H/T
I/P
LO
I/P
HI
A
B
C
D
F
H
J
K
M
N
P
R
Span Pot
1.XXX
1X.XX
1XX.X
1XXX.
Decimal
Select
Header
Decimal Select Header
Cut loop to turn OFF last digit for 199 display
0.8" Optional Display
0.56" Display
Common
Input HI
Input LO
Hold
Test
J5
TST
H/T
HLD
SIG
LO
SIG
HI
AC Neutral
AC Line
240V
120V
AC1
AC2
AC3
AC4
GND
Input HI
Input LO
Hold
470K
5.1K
5.1K
0.22 F
Test
12 Bit
Dual Slope
A to D and
Display Driver
+ 5 V — 5 V
GND
To Display
Span Pot
Zero Pot
Zero Pot
1.XXX
1X.XX
1XX.X
1XXX.
5K
9K53
47K
— 5 V
+ 5 V
+ 1.25V
Zero Pot
40K2
J3
Input
Protection
Circuit
47K
1M
Span
Pot
+ 5 V
— 5 V
Differential
to Single
Ended
Conversion
+ 5 V — 5 V
AC to DC
Conversion
Circuit
1Amp (0.1‰)
or
5Amp (0.02‰)
Shunt
Filter
Circuit
Rectifier
and
Regulator
Circuit
GND
-5 V DC
+5 V DC
!
WARNING
:
AC and DC input signals and power supply
voltages can be hazardous. Do Not connect live wires to
screw terminal plugs, and do not insert, remove or handle
screw terminal plugs with live wires connected.
SPAN Potentiometer (Pot)
The 15 turn SPAN pot is always on the right side
(as viewed from the front of the meter). Typical
adjustment is 100% of the input signal range.
ZERO Potentiometer (Pot)
The ZERO pot is to the left of the SPAN pot (as
viewed from the front of the meter). Typically it
enables the displayed readings to be offset
±500 counts.
1. Apply an input of 0 amps AC to the meter by shorting the
inputs. Adjust the Zero pot until the meter reads 000.
2. Connect the secondary of the current transformer (CT) to
the meter inputs, and apply a known current. For high cur-
rent CTs, a known AC current, proportionate to the CT out-
put, should be used for calibration.
3. Adjust the Span Pot until the meter displays the required
reading for the current being applied.
4. The UM-35ACI is now calibrated and ready for use.
(Whenever a new range is selected, re-calibration is required to
meet the specified accuracy).
1A or 5A
Current Shunt
Zero Adjust
Potentiometer
J5
Input High
AC Amps
Input Low
Span Adjust
Potentiometer
AC Neutral
AC Line
240V
120V
A
B
C
D
E
A
C
1
A
C
2
A
C
3
A
C
4
N/C
A
B
C
D
E
A
C
1
A
C
2
A
C
3
A
C
4
AC2 & 3
Joined
AC2 & 3 Joined
A
B
C
D
E
A
C
1
A
C
2
A
C
3
A
C
4
L M N P R S
10 11 12 13 14 15
L M N P R S
10 11 12 13 14 15
L M N P R S
10 11 12 13 14 15
See below for
connections
