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3-1
Section
Installation
17
Fit the hook of the fitting in the square hole in the body and tighten the screw
with the Philips head screwdriver while lightly pulling the fitting.
Note
1. During work at the panel, do not allow any metal filings or wire strands to
enter the NT21. Otherwise, the product may malfunction.
2. The thickness of applicable operation panel is 1.6 mm to 4.8 mm. All fittings
must be tightened uniformly to a torque of 0.5 to 0.6 N
⋅
m in order to ensure
water- and dust-resistance. Front sheet of NT21 may be warped if the tight-
ening is too strong or not uniformity. The panel must not be soiled or warped,
and must be able to support an installation that will remain secure and
strong. Otherwise, the product may malfunction.
3-1-3 Power Supply Connection
Connect a 24 VDC power supply to the power input terminals.
Caution
Carefully check the wiring before switching ON the power.
Caution
Do not connect AC power to the DC terminals. Incorrect wiring may result in
burning.
Note
1. Depending on how the power is switched ON/OFF, the entire system may
stop. Follow the correct procedure when switching the power ON/OFF.
Otherwise the system may operate unpredictably.
2. Use DC power supplies with low voltage fluctuation. An incorrect power sup-
ply may result in malfunctions.
3. Do not perform a dielectric strength test. Otherwise, the product may mal-
function.
4. If complying with EC directives (low voltage directives), use a power supply
with reinforced insulation (compliance with EC directives is planned for June
1998).
24 VDC
24 VDC
power supply
Circuit
breaker
Power Supply
The applicable power supply specifications are as follows.
Item
Value
Power supply
24 VDC
Allowable power supply voltage fluctuation range
20.4 VDC to 27.6 VDC
(24 VDC
±
15%)
Power supply voltage capacity
7 W or more
