TM_ELF-D_R1C
EBTRON
, Inc. 1663 Hwy. 701 S., Loris SC 29569
•
Toll Free: 800.2
EBTRON
(232.8766)
•
Fax: 843.756.1838
•
Internet:
EBTRON
.com
11
ELF - E
LECTRONIC
L
OW
F
LOW
A
IRFLOW
/T
EMPERATURE
M
EASUREMENT
ELF
DUAL ANALOG OUTPUT
/D
SERIES
ELF/D INITIAL START UP / NORMAL OPERATION
The following procedure is intended for initial start up of the instrument. Following the initial set up, no further user activ-
ity is required during normal operation.
1.
Remove the cover to the electronics enclosure by removing the four screws on the cover.
2.
Make sure that the 24VAC circuit breaker used to power the ELF is turned OFF until all wiring is complete!
3.
Confirm 24VAC connection from the power source to the ELF 24VAC wire (red wire) as outlined in the ELF
24VAC Power Connections section of this document.
4.
Confirm common ground 24VAC and signal ground connection from the power source to the ELF at the black wire.
5.
Confirm ELF/D analog airflow and temperature signal output connections at the white wire and green wire respec-
tively, to the analog input of the BAS as outlined in ELF Analog Output Connections section of this document. Note
that the ground of the BAS must be at the same voltage reference as the ground of the ELF and the power source.
6.
Set the desired analog output options using CONFIG switches SW1 to SW4 as outlined in the ELF Analog Output
Option Switch Settings section of this document.
7.
Activate the 24VAC power source to power on the ELF.
8.
Following a brief instrument initialization, the green Activity LED will continuously flash ON for 1 second, then OFF
for 1 second. This indicates normal operation. In the event of a sensor fault, the LED will produce longer continu-
ous flashes ON for 2 seconds, and OFF for 2 seconds.
9.
Confirm that the BAS is receiving the analog output signals that indicate instrument airflow (or equivalent velocity
pressure) and temperature.
10. Replace the ELF electronics enclosure cover and secure with the four screws removed in step 1.
Converting the Analog Airflow Output Signal from Linear to Volumetric flow - FPM to CFM
The analog airflow output can be converted from velocity (FPM) to an equivalent volumetric flow (CFM) by multiplying the
indicated flow velocity by the free area of the sensor installed location (in square feet). For example, with an ELF/D00
installed in a 12 inch round duct, using the 0-10VDC scale and 3,000 FPM full scale output range options; an airflow
output of 5VDC indicates a flow velocity of 1,500 FPM (5VDC is one-half of the 0-10VDC output, corresponding to half of
the 0-3,000 FPM scale; and equals 1,500 FPM). The ELF installed duct location area in this example is calculated at
0.785 ft
2
(using Pi x duct radius
2
, or 3.14 x 0.5ft
2
). Multiplying the indicated instrument output of 1,500 FPM by the duct
free area of 0.785 ft
2
yields an equivalent volumetric flow of 1,177.5 CFM.
ELF MAINTENANCE
In most HVAC environments, periodic maintenance and calibration is not required or recommended
*
.
*
Depending on the application, it may be necessary to periodically inspect and clean sensors using compressed air or a small brush. Factory performance returns imme-
diately after cleaning. Recalibration is NOT required. Periodic inspection of the sensors is always advised, and accessibility must be considered in these applications.
ELF STANDARD LIMITED PARTS WARRANTY
If any
EBTRON
product fails within 36 months from shipment,
EBTRON
will repair/replace the device free of charge as
described in the company’s warranty contained in
EBTRON
’s Terms and Conditions of Sale. Defective equipment shall
be shipped back to
EBTRON
, freight pre-paid, for analysis.