User's Manual
MS3705HA Slim Plug-In Digital Alarm Setter with Isolated Dual Output (High Accuracy Model)
Rev. 1.60
2
On Wiring:
Connections to the instrument should be made to the terminal
block. For assignment of the terminals, refer to section 6. The
recommended screwing torque is 0.8 to 1.0 Nm.
For lead wires, use a highly flexible stranded conductor. The
recommended nominal cross-section of the lead wire conductor
is 0.5 to 2.0 mm
2
.
The connection of the lead wire to the terminal block should be
made with the insulated crimp terminal attached to the end of the
wire. Without the insulation, short circuit or electric shock may
occur. The recommended thickness of the crimp terminal is 0.7
to 1.0 mm.
Note that only up to two (2) crimp terminals can be connected to
one (1) terminal screw. In this case, the thickness of the crimp
terminal should be not greater than 0.8 mm.
φ3.7
6.8
m
ax
.
3.4 max.
4.6 min.
To Avoid Erroneous Measurements:
In order to reduce the influence of noise, the input/output wire
and power supply wire should not be used in a same bundle or
same conduit. They should be installed separately with a
minimum distance of 200 mm.
Avoid wiring the signal lines in the vicinity of equipment
generating magnetic fields or electromagnetic waves, such as
electric motors and large-scale transformers. If inevitable,
anti-noise measures such as employment of shielded wires are
indispensable.
At least 30 minutes of warm-up is required prior to operation.
Any sensor or equipment to be connected to the instrument
should be selected in consideration of the input/output
impedance of the same. (For detailed specifications, refer to
section 4 or the relevant product specification sheet that can be
downloaded from our website at https://www.mtt.co.jp.)
4. About the Product
The MS3705HA compares the levels of DC current or voltage
signals with two set-points selected using front panel switches and
outputs two independent isolated relay contact closure signals.
Features:
Manual setting by front panel switches, enabling any set-point
within the range of 0 to 105% (in 0.1% steps; but in 1% steps for
the range over 100%).
Relay activation mode and hysteresis settings are possible with
the front panel switches.
Pin and socket contacts are gold-plated (0.2
μ
m) to ensure high
reliability and long-term stability.
High dielectric strength of 2,000 VAC between input, [output 1,
output 2], power, and ground.
The power unit can deliver AC power ranging from 85 to 264V
steplessly without switching to meet varied power requirements.
Plug-in type for better maintainability
Drop-proof terminal screws for ease and safety of installation
Fuse installed in the power line as standard.
Specifications
Input Resistance
Voltage input:
1M
Ω
min. with or without power.
Current input: 250
Ω
(Standard for 4-20mA DC)
Allowable Input
Voltage
Voltage input: 30V DC max., continuous.
(Standard for a span up to 10V)
Current input: 40mA DC max., continuous.
(Standard for 4-20mA)
Output
Two independent form C relay contact closure
signals
Trip Points
Setting: Through the front-accessible setting
switches.
Range: 0 to 105% of span (in 0.1% steps; but
in 1% steps for the range over 100%)
Accuracy: Better than ±0.1% of span
Hysteresis: 0.5 to 50%±0.1% of span
Note: The upper and lower hysteresis limits are
respectively 110% and -10% of span.
Relay Status
Indicator LED
Red LED lights up when the relay is activated.
Relay Activation
without Power
COM and NC are closed for each output.
Relay Start-up
Limitation
The relay gets ready for action 2 seconds after
power-up.
Temperature
Effect
Better than ±0.15% of span per 10°C change in
ambient.
Response Time 150ms max. (0-90%) with a step input at 100%.
Insulation
Resistance
100M
Ω
min. (@ 500V DC) between input,
output 1, output 2, power, and ground.
Dielectric
Strength
Input / Output 1 / Output 2 / [Power, Ground]:
2000V AC for 1 minute (Cutoff current: 0.5mA)
Power / Ground: 2000V AC for 1 minute (Cutoff
current: 5mA)
Relay Contacts
Rated load: 5A 125VAC, 5A 30VDC
Maximum allowable voltage: 250VAC, 30VDC
Maximum allowable current: 5A (NO) / 3A (NC)
Electrical life:
5A 250VAC (NO): 50×10
3
cycles
(Frequency: 1,800 cycles/h)
5A 30VDC (NO): 100×10
3
cycles
(Frequency: 1,800 cycles/h)
Mechanical life:
5×10
6
cycles (Frequency: 18,000 cycles/h)
Surge Withstand
Capability
Tested as per ANSI/IEEE C37.90.1-1989.
Storage
Temperature
-10 to 60°C
Installation Position
Typical Installation Example