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High Temperature Thermocouple
This thermocouple is used for the high-temp shutdown. The system shuts down if an open
circuit, short-circuit or short-to-ground is detected on this thermocouple. It should be placed
in the same thermowell as the Process thermocouple using a dual element thermocouple.
AUX Thermocouple
This thermocouple is optional and can be enabled in menu 5. It can be used to monitor stack
temperature or to control a secondary process temperature. The system shuts down if an
open circuit is detected and the AUX thermocouple is enabled.
All Thermocouples Must Be:
Isolated from ground
Isolated from power
Type-k thermocouples
Connected with 20 AWG or larger Type-k extension wire
Placed a safe distance from high voltage lines and shielded when necessary
STATUS CONTACT
The status contact is a dry contact output containing a solid state relay. It acts as a switch that the
PF2100 controls. Neither contact is internally connected to power or ground so these connections must
be provided externally as required. When the system is running, the contacts are internally connected
together and when the system is not running, the contacts are open circuited. These contacts are often
used for monitoring the PF2100’s status remotely. An alarm, siren, trouble lamp, or PLC are examples of
devices that might use this contact.
THE STATUS CONTACTS ARE RATED FOR DC ONLY so it is important to observe the correct polarity
when attaching a device. The positive status contact terminal should always be at a voltage potential
greater than or equal to the negative terminal. Do not exceed the voltage and current ratings which are
40VDC, 250mA. The impedance when closed is15Ω. There is a fuse on the status contact to protect it. A
spare fuse is also included.
DRY CONTACT INPUTS
There are 6 dry contact inputs on the PF2100. The expected connection to each of these is a switch.
These contacts must all be closed (shorted) in order for the system to start. Jumpers are provided for
each of these by default. If you need to use a particular contact for your application, simply remove the
associated jumper and connect a switch in its place.
Start Contact
The Start Contact can be used to attach a remote start/stop switch. This is often connected
to a PLC dry contact output. When the contact is open, the system is stopped. For safety
reasons, a double action is required to start the system remotely via this contact. This is
accomplished by closing the switch, opening it, and then closing it again. Once the system is
running, open the switch again to stop it.
ESD Contact
The ESD Contact can be used to attach an emergency shutdown switch. This is often
connected to a mushroom switch mounted on a remote panel or to a PLC dry contact output.
When the contact is open, the system is stopped. The system cannot be started via this
contact but this contact must be closed in order to start the system.
Proof of Closure Contact
The Proof of Closure Contact can be used to receive the feedback signal from a Main Valve
that has a Proof of Closure output. If multiple main valves with Proof of Closure outputs are
used, these can be wired together in series. Before the system attempts to light the pilot, it
will check that the Proof of Closure Contact is closed. If it is open, it will not light the pilot.
High Pressure Contact
The High Pressure Contact can be connected to a High Pressure Switch installed in the fuel
train. Typically, this switch is placed immediately after the Main valve in the fuel train. See the
4-20mA Expansion Card section for more details.
Low Pressure Contact
The Low Pressure Contact can be connected to a Low Pressure Switch installed in the fuel
train. Typically, this switch is placed immediately before the Main valve in the fuel train.
The Low Pressure Contact operates using averaged time to help reject brief fluctuations
in gas pressure. The contact must be open continuously for 2 or 6 seconds (depending on
the “Pressure/Level Delay” setting) before the system will shut down. If “Auto Restart” is
enabled, the system restarts automatically when the Low Pressure Contact re-closes. See
the 4-20mA Expansion Card section for more details.
IGNITION COIL / FLAME DETECTION
This section provides some tips to set up the system for reliable ignition and flame detection.
Internal vs. External Coil
If less than 5m (15ft) of ignition wire is required to connect the PF2100 to the burner
housing, the internal coil configuration can be used. Otherwise the external coil configuration
must be used.
The PF2100 system is available with an internal coil or an external coil can be purchased with
or without a separate enclosure.
Wire Lengths
When wiring the ignition and flame detection circuits, the wire length must be carefully
considered. If the wire lengths are too long, the PF2100 may not be able to deliver enough
energy to the ignition rod to ignite the pilot. The PF2100 may also fail to receive a signal from
the flame rod for detecting flame.
Grounding
Properly grounding the pilot assembly back to the PF2100 is critical for proper ignition and
flame detection. A ground wire should run from the Ion - or EGND terminal of the PF2100 to
the pilot assembly. This wire can either be connected to a ground screw on the pilot bracket
or to the burner housing. If connected to the burner housing, use a multimeter to verify that
the burner housing has electrical continuity with the pilot assembly. If not, another wire must
be added to connect it.
Single Rod vs. Dual Rod
A single Kanthal rod can be used for both ignition and flame detection to save cost if desired.
This often results in a performance trade-off between ignition and flame detection. This
option is only available with external coils.
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