Lakeshore Learning Materials 642 - Manual (Page 35)

Lake Shore Model 642 Electromagnet Power Supply User’s Manual
Installation 3-7
3.3.7 Mains Wiring
No cord or disconnecting plug is provided with the unit. In all cases, the field connection of the mains wiring shall
comply with all local wiring codes where the Model 642 is installed. The power source shall be protected with a
dedicated circuit breaker or fuse. The rating of the protection device shall be a value equal to that of the internal breaker
or the next higher commercially available value (See Table 3-2). If the Model 642 is connected with permanent wiring, a
disconnect switch shall be installed. The disconnect switch shall be located within 3 meters (10 feet) of the Model 642,
be clearly marked in layman’s language and be easily accessible.
3.4 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 642 output. If a switch is not used, a jumper is
required. 24 VAC at 1 A is provided to operate a solenoid water valve for the magnet. 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.
NO VALVE OR SWITCH VALVE ONLY SWITCH ONLY VALVE AND SWITCH
Figure 3-8. Typical Magnet Connector Wiring
3.5 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 642. 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 642 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 3-9 shows some typical Auxiliary Connector wiring.
NO SWITCHES EMERGENCY STOP
&
REMOTE ENABLE
ALARM CONTACTS
TO REMOTE ALARM CIRCUIT
Figure 3-9. Typical Auxiliary Connector Wiring