RKI Instruments 1017-05 - Manual (Page 7)

Model 1017-05 Operator’s Manual • 3
Figure 2: Model 1017-05 Flow Diagram
Subpanel Assembly
All the internal components of the Model 1017-05 are part of the subpanel assembly. It is
mounted to the inside of the housing. The subpanel assembly consists of an aluminum
subpanel with the following components mounted on it: the terminal plate, the inverter,
the pump, the sensor block, and the combustible sensor (see Figure 1).
Terminal Plate
The terminal plate is mounted on the right side of the subpanel. Two terminal strips for
external wiring are located on it. The sensor terminal strip is at the top of the plate. It is a
four point terminal strip used to connect the sensor to an external controller. The power
input terminal strip is a two point terminal strip located below the sensor terminal strip. It
is used to connect 24 VDC to the Model 1017-05.
Inverter
The inverter is located on the subpanel below the terminal plate. It is held in place by the
terminal plate and is prevented from sliding out by screws which are screwed into the
subpanel. A foam pad installed on the subpanel below the inverter helps keep the inverter
in place.
The inverter takes the 24 VDC from the power input terminal strip and converts it to 24
VAC for use by the pump.
Pump
The pump is mounted to a bracket on the subpanel to the left side of the sensor terminal
strip. It draws the gas sample into the Model 1017-05 through the inlet fitting and
exhausts it through the exhaust fitting. The pump operates on 24 VAC which is generated
by the inverter.
Sensor Block & Combustible Sensor
The sensor block is mounted to the subpanel below and to the left of the pump. It is made
of aluminum. It provides a chamber for sample to flow over the combustible sensor. The
sensor is pushed into the sensor block and an o-ring seal in the block seals the chamber.
The sensor is held in the sensor block by a a retaining plate. Two captive panel screws
hold the retaining plate on the sensor.
The sensor is an NC-6245 combustible gas sensor. It is a catalytic combustion sensor and
consists of two sensing elements enclosed in a stainless steel body. A porous stainless steel
flame arrestor allows sample to diffuse into the sensor. Five pins extend out the rear of the
sensor. These pins mate to a five position socket that is wired to the sensor terminal strip.
Pump
In
Inlet LEL Exhaust
Out