M970-07/04
PAGE 10
Model 970 – 2 and 970 – 1
(8) Temperature control :- Centre zone master controller with
input range 0 to 1200 degC.
2 x end zone “slave” controllers
with input differential range of
+/- 7 mV. (+/-200 deg.C.)
(9) Over temperature trip controller :- 0 to 1200 deg.C. range to 1 deg.
C.resolution with relay closure
output on overtemp.
(10) Control / measurement thermometers :- Centre zone : 4 x N type TC
1- centre zone control
2- end zone control differential
1- independent overtemp. alarm
& front socket indication.)
End Zone: 2 x N type TC -1 in each
end zone centre for end zone
differential control.
2 x separate end zone indication
TC’s on front panel positioned 2.1
ins.(53mm.) from inside each end
of outer end zone winding at 3.0 ins
(75 mm.) inside outer end of main
furnace body.
(11) Electrical isolation & safety :- Supply input , 2 pole isolation circuit
breaker and over current protection
trip for single phase or 3 pole for 3
phase.
3 pole latching isolation relay to
heater power regulators / heaters
with main latching furnace power
ON and OFF indicator push button
switches linked to independent over
temp TC alarm to isolate heater
power via 3 pole heater power relay
