Operation & maintenance, Flow rate (gpm) – Seametrics EX800-Series User Manual

Page 11

Advertising
background image

30Vdc

Max. 6m

A

- +

- +

12-24Vdc

3 4 5 6

2

1

Power

Forward

Output

Zero

Adj

Status

LED

NOTICE

Wa
rranty is void if

unauthorized repair

is attempted!

OPERATION & MAINTENANCE

Zero Adjustment.

When the EX800-Series is powered up

and there is no flow, there should be no output pulses (or, if
connected to the FT420, flow rate should read “0”). If there
are pulses it may be necessary to adjust the flow meter under
no-flow conditions after it has been installed. This should only
be done if the indicated flow is low, near the lower cutoff.

To perform the adjustment, after determining that there is a full
pipe with no flow

, short between the two pins marked “Zero

Adjust”. A red LED light will come on for approximately 50
seconds and then go out. The zero adjustment is completed.

Minimum Flow.

As with any other flow sensor, there is a rate

below which the EX800-Series sensor cannot read. Check the
flow rate table below for the minimum flow rate detectable by
the sensor for a given pipe size.

Presence of Flow Indication.

To assist in troubleshooting,

the “Status LED” has two blinking modes in normal operation.
When there is no flow detectable by the meter (below minimum
threshold) the LED blinks every 8.0 seconds. When there is
detectable flow, the same indicator blinks every 3.0 seconds.

Filtering.

The software of the EX800-Series sensor filters out

electrical noise and averages sudden variations in the flow to
smooth the output. It takes a matter of seconds for the flow
sensor to get up to full output when it is powered up or when
flow begins.

Calibration (“K-factor”).

The K-factor represents the actual

number of pulses per gallon the meter produces during a flow
test. This number can be entered into your electronic control
to make it read properly. If the EX800-Series meter is ordered
with a tee fitting, it is factory-calibrated in the fitting and the
K-factor is indicated on the side of the fitting (see diagram).

Find Your K-Factor Here

Page 9

Zero

Adjust

Pins

Electrode Coating.

Grease or other adhering, non-conductive

materials can stop flow detection if the electrodes become
heavily coated. To clean the electrodes, remove the sensor
from the pipe and gently scrub the electrodes (three silver
bumps) on the reading face of the flow sensor. A mild soap
(dishwashing liquid for example) can be used to aid the
cleaning process.

10031295

EF81T-P200

K:158.42

If the EX800-Series meter is ordered with a saddle or wel-
dolet fitting

, find your K-factor in the chart below.

3” 4” 6” 8”

10” 12”

K-FACTORS SADDLES & WELDOLETS

Status

LED

PVC/Steel

Sch. 40

PVC/Steel

Sch. 80

Stainless

Steel (10S)

Stainless

Steel (40S)

Copper Tubing

(Type L)

Copper Tubing

(Type K)

Brass Pipe

Duct. Iron

(Class 52)

70.397

78.748

62.385

70.397

76.371

78.371

70.672

57.376

40.985

45.360

36.626

40.985

43.552

44.638

41.517

37.320

18.130

20.084

16.510

18.130

19.513

20.223

17.778

16.915

6.674

7.322

6.173

6.674

7.230

7.500

6.674

6.197

10.497

11.495

9.642

10.497

11.201

11.622

10.445

9.503

NOTE:

K-factors are in Pulses/gallon. For Pulses/Liter, divide

by 3.785.

4.709

5.184

4.373

4.661

5.016

5.239

4.661

4.325

1” 1-1/2” 2” 3” 4” 6” 8” 10” 12”

• Min

.7

1.5

2.7

6

11

25

44

69

99

@ 0.28 ft/sec
• Max

49

110

196

440

783 1760 3130 4900 7050

@ 20 ft/sec

FLOW RATE (GPM)

Nominal

Pipe Size

Reverse Output Option

Advertising