Operating instructions

12/23/2011 17 EI711A
See pages 9 and 10 and review routing comments
Bad sensor, operating default condition – the detection of bad sensor forces the controller to a fixed
stage operation.
- OT sensor
 Stages 1 and 2 on, stages 3 and 4 off (5 kW maximum)
 If the switchover set point is 0° or less, will go directly to standby
 The WF-ANZ screen reads “254”
- ST sensor
 Stages 1 and 2 on, stages 3 and 4 off (5 kW maximum)
 The WF-ANZ screen reads “254”
Analyzer readout, sensor temperature constant 32° or 0° – these two values represent digital bit
patterns that are hard to predict an error function. A blinking green light may or may not be experienced.
Typically the cable is too long, wrong type of sensor wire, or some electrical interference on the sensor
cable.
MANUAL RESET
Located behind the hinged control board door is a 250°F manual reset. This breaks the circuit for all
electric elements. However, connected in the same circuit loop is the automatic reset 180° hi-limit.
Normally the automatic reset should always take care of any overheat condition prior to popping the
manual reset. Therefore, you should not experience a manual reset condition unless there has been a true
hardware failure.
Two exceptions – a standby furnace (or wood furnace) having an outlet temperature greater than
250°F or cold startup without blower. Because of the sensitivity of this capillary manual reset,
anytime there is a blower failure when the elements come on you can expect a manual reset.
SYSTEM AIRFLOW
Follow the power-up instructions, next section, or within the warranty report procedure EC110. Also see
page 16, WF-ANZ can now, real time, calculate CFM.
1. SYSTEM TEMPERATURE RISE - The overall temperature rise (both sides of Electro-Mate)
must be less than 50 F. If any portion of the plenum top is operating with an air temperature
greater than 125°F, element life will be shortened.
A. CFM CALCULATION, THIS ELECTRO-MATE
- By measuring the temperature rise
across the Electro-Mate, the actual CFM can be quite accurately determined. The airflow
and Electro-Mate unit must be operating in a stable condition for at least 10 minutes. If it
is cycling on temperature limit, this calculation will be of no value. The accuracy of this
formula will depend upon uniform and average temperature rise plenum thermometer
readings and the accuracy of both the clamp-on amp meter and AC voltmeter. NOTE:
The volts x amps x 3.4 value is the same as Btuh output.
Volts x Amps x 3.4
CFM =
Temperature Rise x 1.08
B. CALCULATED CFM, OIL/GAS FURNACE - By measuring the temperature rise across
the existing furnace, the CFM can be approximated. The accuracy of this formula will
depend upon the estimated or determined Btuh output (actual heat energy across the
furnace). You cannot use name plate Btuh values. You must use a realistic estimated or
measured true OUTPUT Btuh.
Btuh (output)
CFM =
Temperature Rise x 1.08