Future Design MCTB 4.3, User Manual

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MCTB
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3 Wiring
This section describes the methods and precautions for wiring the MCTB system components.
3.1 Power Requirements
The MCTB control system touch screen operates on a nominal 24VDC supply voltage with an allowable range
of 11 to 36VDC. The B42 loop controls can be ordered to operate from either a DC (11-26VDC) or an AC (90-
250VAC) supply. Do not power the MCTB controller components and highly inductive DC loads or input circuitry
to other equipment with the same DC power supply used for the MCTB.
If the MCTB is installed in an area with poor power quality or frequent power interruptions, it is recommended
that a time delay-on relay be installed in the power supply wiring to all components of the MCTB. This will
prevent rapid on-off cycling of the MCTB during brown-out or momentary power interruptions. Rapid power
cycling to MCTB can cause damage to the electronics and/or loss of data.
3.1.1 Installing the Power-On Delay Relay
Due to the rate at which AC/DC power supplies reach their nominal supply voltage after application of power,
the relay contact of the timer should be installed between the output of the power supply and the power input
of the MCTB control system components. This allows the power supply output voltage to reach its nominal
value prior to connecting the MCTB to its output terminals.
WARNING:
•
Turn off power to the MCTB before starting installation, removal, wiring,
maintenance and inspection of the MCTB controller. Failure to turn off
power may cause electric shock, create a fire hazard or cause damage
to the MCTB.
•
Emergency stop and interlocking circuits MUST be configured outside
of the MCTB control system. If such circuits are made through the
MCTB, failure of the MCTB control system may cause uncontrollable
operation, damage to equipment or accidents.
CAUTION:
•
This section presents recommended installation practices and
procedures. Since no two applications are identical, these
recommendations should be considered as guidelines. The system
designer should be aware that devices in control systems could fail and
thereby create an unsafe condition.
•
Electrical interference in an operator interface can lead to equipment
start-up, which could result in property damage and/or physical injury
to the equipment operator.
If the application requires an operator or attendant, you should be
aware that this potential safety hazard exists and take appropriate
precautions. Consult NEMA ICS 3-304 for more information regarding
safety for the installation of solid-state programmable control devices.