Black & Decker DCM200C Guide d'installation télécharger pdf (Page 28)

DCM 200 Installation

Page 28

6.5. Technical: Pump Frequency-Stroke Controls

1 Gallon = 3785 mL. Set pump frequency control to External & Stroke to 100%

GPH = Gallons per hour GPD = Gallons per day

Pump Defaults – User Adjustment Range & Resolution

Pump default mL/stroke is set for a 25psi head, typical for chemical injection piping.

The user mL/stroke adjust is limited to +25% and –70% for ProMinent pumps.

The user mL/stroke adjust is limited to 0.01mL/stroke and 10ml/stroke for ‘Other’ type pumps.

In both cases the adjust resolution is 0.01mL

‘Other’ type Pump SPM rates are limited to a minimum of 50 SPM and a maximum of 400 SPM

Maximum Feed Rate

A pump’s maximum feed rated is it’s rated maximum strokes/minute x mL/stroke.

Example: A ProMinent Beta 1602 pump is rated 180 SPM with a default of 0.24 mL/stroke @ ½ rated

backpressure.

The maximum feed rate for this pump = 180 x 0.24 x 60 = 2592 mL/hour, 0.685 GPH, 15.44 GPD

At the –70% minimum user adjust: 0.78 L/hour, 0.2 GPH

At the +25% maximum user adjust: 3.24 L/hour, 0.856 GPH

Minimum Feed Rate or Turn Down

The minimum pump frequency is set to 0.1 SPM; a turn down of 1800:1 for a 180 SPM pump

and 2400:1 for a 240 SPM pump.

The 0.1 SPM limit turns the pump drive LED ON for 5 minutes and OFF for five minutes; a maximum for

an observer visually verifying that a pump is stroking.

Minimum feed rate only applies to pumps that are controlled by analog sensors; pH, ORP, temperature,

flow rate…

Other pump controls operate at either the user set mL/minute or MAX SPM, so minimum feed rate is

not applicable.

Control Resolution

Control resolution = 1mS. 1mS defines the precision of pulsed output variable frequency control. The

DCM 200 controller calculates pulsed output strokes per minute to the nearest 1000

of a second

(1mS), based on deviation from setpoint and other factors like PID control calculations.

Example: At 180 SPM, the pump pulses 3 times per second. At 179 strokes per minute the pump

strokes 2.983 times per second. The number of times per minute, to the nearest 1mS control resolution

is 667 feed rates between 179 and 180 SPM. At 10 SPM, with 1mS control resolution, up to 6000

calculated feed rates are possible.

As the example clarifies, control resolution is more important at high pump speeds, and much more

control precision than Time Modulated control.

6.6. Relay & Frequency Controls Comparison

6.6.1. ON/OFF Controls :

Relays R1 to R3 are used for ON/OFF controls.

The relay switches 120VAC ON or OFF, powering pumps, solenoids and motorized valves.

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Black & Decker DCM200C Guide d'installation Page 28