Precision Control Systems 915 - Manual (Page 10)

Page 7 of 21
Remote Interlock Switch
This feature provides for remote process interlock shutdown of the heater power. This is
accomplished by opening the heater power controller contactor. With the interlock open, the
heater can not be turned on from the control system front panel. The switch contacts must be
open during the heater off condition. If this feature is desired, connect using the following
procedure:
• Remove the factory installed jumper at TB 100 pins 10 and 11.
• Connect the normally open contacts of the switch to TB 100 pins 10 and 11.
• If more than 1 interlock switch is used in a system, wire the contacts in series and then
connect to the system.
Heater Open Switch Interlock
This feature provides shutdown of the heater power if the heater is opend during operation.
This switch directly interlocks power to the heater contactor. If a heater cavity open switch is
not included with your heater, use a switch with contacts that are open when the heater is
open. To implement feature, connect using the following procedure:
• Remove the factory installed jumper at TB 100 pins 14 and 15.
• Connect the normally open contacts of the switch to TB 100 pins 14 and 15.
• If more than 1 heater open interlock switch is used in a system, wire the contacts in
series and then connect to the system.
Note:
If a remote Emergency Stop switch is desired, wire the switch (push/pull type with maintained
contacts) in series with the heater open switch.
Remote Setpoint Input
This feature allows the power level of the system to be controlled from a remote location or
device. This is accomplished by applying a 0-5 VDC or 0-20 mA signal input from a remote
source. This feature is not available when the “Temperature Controller” option is installed. If
this feature is desired use the following procedure.
• For a 0-5 VDC input, connect the source to TB 100 pins 16+ and 17-.
• For a 0-20 mA input, connect the source to TB 100 pins 16+ and 17-. Also install a 250
ohm resistor across terminals TB100 16+ and 17-.
Temperature Control Option Connections (Option Codes TCT & TCP)
Temperature control option “TCT” is setup to use a ‘K’ type thermocouple for the temperature
input. Temperature control option “TCP” is setup to use a pyrometer for the temperature input.
Alarm connections are provided if required for your process. The alarm contacts are ‘dry’ type
rated for a maximum of 3 Amps resistive at 240 VAC. If desired the process temperature
alarm may be connected to the Front Panel Over-Temp Alarm Indicator. Make connections as
follows:
• “TCT” option: Use ‘K’ type extension wire from the thermocouple to the system
connections. Connect the ‘K’ thermocouple extension wire to TB 100 pins 18+ and 19-.
• “TCP” option: The pyrometer should source the 4-20 mA current through its circuitry. If a
‘2 wire’ pyrometer is used, an external power supply must be used. The model 935 does