Component Summary; Switches And Indicators; Protective Fuses And Relays - Parr Instrument 4838 Operating Instructions Manual

4838 Reactor Controller

Component Summary

Switches and Indicators

Front side
4838 Reactor Controller
The Heater Switch is a manual, three-position, illu-
minated switch which controls the amount of power
sent to the heater. In the HIGH (II) position, full
power is developed by the heater. In the middle (0)
position the heater is off. In the LOW (I) position, a
diode is switched into the system to allow only one-
half of the rated voltage to be supplied to the heater.
This low setting will be most useful when operating
the reactor at temperatures below 175 °C. Power
for the heater is supplied through a solid state relay
controlled by the temperature control module. The
light in the heater switch will glow only when cur-
rent is fl owing to the heater.
The high limit indicator light will glow if the control-
ler receives an indication from any of its sensors
that a high temperature or high pressure limit has
been reached and the High Limit Reset has opened.
When the light comes on, the user must fi nd the
source of the problem, correct it, and then manually
reset the system using the high limit reset button on
the front of the controller.
The Main Power Switch will cut off power to the
controller. Take care to position the controller such
that the main power switch may be accessed easily
when the controller needs to be disconnected.
8
Back side
4838 Reactor Controller 115V

Protective Fuses and Relays

An instrument fuse is mounted on the back panel.
This is a Fast-acting, 250VAC, 1.0 amp fuse, intended
to protect the temperature control module and any
installed display modules.
A load fuse is mounted on the back panel on 115V
systems. This fast-acting, 250VAC, 20 amp fuse is in-
tended to protect the controller and prevent electric
shock hazard from fault from occurring.
Two load fuses are mounted on the back panel
on 230V systems. These are fast-acting, 20 Amp,
250VAC and are intended to protect the controller
and to prevent electric shock hazard from fault from
occurring.
Caution!
Unplug unit before servicing. For continued
protection against possible hazard, replace
fuses with same type and rating of fuse.