Hanna Instruments bl 7917 User Manual

TROUBLESHOOTING GUIDE

ELECTRICAL

The pump does not operate when turned ON:

• Check the power supply and connections. Voltage should be

between 100 - 130 VAC for 115 V models and between 200
- 250VAC for 230 V models.

• See Installation section on page 11 or call your dealer or the

nearest Hanna Customer Service Center for technical assis-
tance.

OPERATING

Display does not indicate:

• Check that the pump is properly plugged in
• Check the fuse.

Display shows 1 on the far left hand side:

• Check electrode and/or electrode cable.

"No Dosage" LED is lit:

• Check the tank where the level controller is working or verify

the connection on the terminals (they must be short for the
pump to dose).

LIQUID

The pump operates but does not prime:

• Check for a clogged or loose filter on the suction valve

assembly. Retighten if necessary.

• Check to see if the pump is too high above the foot valve

assembly (HI721005) in the feed tank. This vertical distance
should not exceed 1.5 meters (5 feet). Either lower the pump
or raise the feed tank.

• Check the pump head, suction and discharge valves for

blockage.

Pump flow rate is reduced:

• Check the pump head, discharge and injection valve assembly

for any clogging. Clean and reassemble.

• Check for any additional back pressure created since the last

flow rate was conducted.

• Check for any changes in the viscosity of the chemical being

used.

• Be sure that valves have been properly installed in the pump

head.