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CHAPTER 2: INSTALLATION
875DP/500DP/500HV DUAL PULSE
RESISTANCE WELDING
POWER SUPPLIES
2-4
990-290
(F)
AIR VALVE DRIVER 1 - Provides either 24 or 115 volts (AC) to Unitek Peco air actuated weld
heads. AIR VALVE DRIVER 2 is an optional output which is used to control a second air actuated
weld head.
(G)
REMOTE DATA BUS - 25 pin, sub-miniature "D" connector used to interface with other Unitek
Peco devices.
(H)
CONTROL SIGNALS - 15 pin, sub-miniature "D" connector used for Remote Schedule Selection.
See Chapter 10.
(I)
OUTPUT POWER CABLE - 5 foot cable is used to connect the power supply to the external
transformer.
Firing Switch Connections
Connect the weld head or hand-piece to the appropriate firing cable or switch located on the rear panel of
the power supply.
Mechanical Firing Switch
Unitek Peco weld heads and hand-pieces are force fired and have two-pin firing switch connectors
which can be connected directly to the mating connector of the MECHANICAL FIRING SWITCH
located on the rear panel of the power supply.
Users of manually actuated weld heads which do not have force firing switches must connect the two
pins in the mechanical firing switch to an external switch in order to initiate the power supply.
Air actuated weld heads which do not have force firing switches rely on the squeeze time to ensure that
the weld head has time to close and apply the proper force to the workpieces. Use the squeeze time
option and select NO FIRING SWITCH from the Options Menu (refer to Chapter 3).
Optical Firing Switch
Users of weld heads with pressure switches using a 3-wire switch or an optical device should use the
OPTICAL FIRING SWITCH receptacle located on the rear panel of the power supply (refer to
Appendix A under
Initiation Switch).
3-Wire Firing Switches
Users of weld heads with single pole, double throw, 3-wire pressure switches should also use the
OPTICAL FIRING SWITCH connector. The power supply will automatically detect that the system is
using a 3-wire switch if Pin 2 is low at power-up.