Hf Pulse Input With Automatic Conversion; Pulse Generator Connection - Honeywell Elster EK280 Applications Manual

EK280

4.4 HF pulse input with automatic conversion

The EK280 can only count pulses from a high frequency pulse generator via an external power supply, and
not battery power. To ensure uninterrupted gas volume measurement, the EK280 can be configured so that
it switches to a low frequency pulse generator in the event of failure of the external power supply.
With a functional external power supply volumes and loads (Vb, Vm, Qb, Qm) can be measured by the high
frequency pulse generator. Should the high frequency pulse generator fail (i.e. due to external power supply
failure) the EK280 automatically continues measurement with the low frequency pulse generator.

4.4.1 Pulse generator connection

Danger!
For EK280 with integrated power supply, the mains voltage must be switched off before
opening the housing, ensure it is not turned back on and verify that there is no voltage.
Pulse Generator
LF
(Reed contact)
Connect the gas meter's low frequency pulse generator (LF reed contact) to terminal "DE1" of the
EK280.
Connect the gas meter's high frequency pulse generator (HF Namur) to terminal "DE2" of the EK280.
Respect polarity, i.e. connect the impulse generator's "+" to the "DE2 +" terminal and "-" with
"DE2 -".
Release the inputs 1 and 2 (terminal "DE1" and "DE2") calibration seals.
Application Manual
DE1 DE2
+ - + -
+ -
Pulse Generator
HF
(Namur)
15