RKI Instruments RM-5000 Series Indicator/Alarm Unit - Manual (Page 16)

4 How to Use 4-3. Precautions for system designing
RM-5000 - 16 -
Do not install the indicator/alarm unit in a place exposed to direct sunlight or sudden changes in the
temperature.
When you select installation sites, avoid a place where it is exposed to direct sunlight or radiant heat
(infrared rays emitted from a high-temperature object), and where the temperature changes suddenly.
Condensation may be formed inside the indicator/alarm unit, or the indicator/alarm unit cannot adjust to
sudden changes in the temperature.
Keep the indicator/alarm unit (and its cables) away from noise source devices.
When selecting installation points, avoid a place where high-frequency/high-voltage devices exist.
Do not install the indicator/alarm unit in a place where maintenance of the indicator/alarm unit cannot be
performed or where handling the indicator/alarm unit involves dangers.
Regular maintenance of the indicator/alarm unit must be performed.
Do not install the indicator/alarm unit in a place where the machinery must be stopped when maintenance is
performed in its inside, where parts of the machinery must be removed to perform maintenance, or where
the indicator/alarm unit cannot be removed because tubes or racks prevent access to it. Do not install the
indicator/alarm unit in a place where maintenance involves dangers, for example, near a high-voltage cable.
Do not install the indicator/alarm unit in machinery which is not properly grounded.
Before installing the indicator/alarm unit in machinery, the machinery must be grounded properly.
Do not install the indicator/alarm unit in a place where other gases exist around it.
The indicator/alarm unit must not be installed in a place where other gases exist around it.
4-3. Precautions for system designing
Using a stable power supply
The external output and alarm contact of the indicator/alarm unit may be activated when the power is turned
on, when momentary blackout occurs, or when the system is being stabilized. In such cases, use a safety
power supply, or take appropriate actions on the receiving side.
The indicator/alarm unit must be provided with the following power supply.
Power supply
voltage
24 VDC (21.6 – 26.4 VDC) (Terminal voltage of the indicator/alarm unit)
Allowed time of
momentary
blackout
Up to 10 milliseconds
(To recover from the momentary
blackout for 10 milliseconds or more,
restart the indicator/alarm unit.) Example of actions
To ensure continuous operation and
activation, install a protective power
supply outside the indicator/alarm unit.
Others
Do not use it with a power supply of
large power load or high-frequency
noise. Example of actions
Use a line filter to avoid the noise source
if necessary.
Heat radiation designing
When it is installed in the closed instrumentation panel, attach ventilation fans above and below the panel.
Introducing protective measures against lightning
If cables are installed outside the factory/plant, or if internal cables are installed in the same duct as the
cables coming from outside the factory/plant, "lightning" will cause problems. Because lightning acts as a
large emission source while cables act as a receiving antenna, devices connected to the cables may be
damaged.
CAUTION
An unstable power supply and noise may cause malfunctions or false alarms.
The descriptions in this section must be reflected on the designing of a system using the
indicator/alarm unit.