3.4.7 Mains Wiring
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3.4.7 Mains Wiring
No wiring is provided with the unit. In all cases, the field connection of the mains
wiring must comply with all local wiring codes where the Model 648 is installed. The
power source must be protected with a dedicated circuit breaker or fuse. The rating of
the protection device must be a value equal to that of the internal breaker setting or
the next higher commercially available value (TABLE 3-2). Wiring must be provided
with a minimum sizing requirement of 6 AWG (13 mm2). A disconnect switch must
be installed within 3 meters (10 ft) of the Model 648, marked clearly in layman’s
language, and easily accessible. Ensure the unit is positioned to allow for easy access
to the disconnect switch.
Do not attempt to connect the power mains using a detachable cord. The power wiring
must be permanently wired to the facilities main wiring by a qualified electrician. Failure
to comply could result in injury or death to personnel.
3.5 Magnet
Connector
The magnet connector provides terminals for an optional magnet temperature
switch or magnet water flow switch and an optional magnet water control solenoid
valve. The flow or temperature switch must have a normally closed contact rated at
5 V at 10 mA. A contact closure is required to enable the Model 648 output. If a switch
is not used, a jumper is required. To operate a solenoid water valve for the magnet,
24 VAC at 1 A is provided. This output is controlled by the power supply, either
automatically via software, or manually through the magnet water menu.
Water control is desirable to reduce water consumption when the water comes from
a municipal facility. Turning the water off when it is not required also reduces the
probability of condensation on the magnet or connecting hoses. If the cooling water
comes from a facility chiller system, condensation is not usually a problem and a
control valve is not required. In this case, it is appropriate to install a flow switch
(optional) or temperature switch (optional) to monitor the water flow and protect the
magnet in the event of a water flow interruption. FIGURE 3-8 shows examples of
typical magnet connector wiring.
Typical magnet connector wiring
WATER
VALVE
SWITCH
FLOW
SWITCH
VALVE
WATER
FLOW
SWITCH
VALVE
WATER
FLOW
SWITCH
VALVE
WATER
FLOW
NO VALVE OR SWITCH
VALVE ONLY
SWITCH ONLY
VALVE AND SWITCH
3.6 Auxiliary
Connector
The auxiliary connector provides terminals for an emergency stop, contacts for a
remote alarm, remote enable and a chassis connection. The emergency stop must
have a normally closed contact rated at 24 V at 1 A. When the contact is opened, it
turns off the Model 648. If an emergency stop switch is not used, a jumper is required.
A normally closed or normally open contact is provided to control a remote alarm
annunciator. This set of contacts is rated at 30 V, 1 A. If it is desirable to have a
remotely located alarm to echo the internal alarm, these contacts can be used with
an external power source and external alarm. The remote enable switch must have a
normally closed contact rated at 5 V at 10 mA. Contact closure is required to enable
the Model 648 output. If a remote enable switch is not used, a jumper is required.
FIGURE 3-8 shows some typical auxiliary connector wiring. A chassis terminal is
provided in the event that any of the wires require a shield to minimize noise.
FIGURE 3-8
