Converting a float switch level control set-up to Ultrasonic Level Instrument (Pulsar)

Well how is the float switch currently wired - presumably there form A, B or C (NO NC or change-over) contacts that trigger when the float reaches a position corresponding to a certain level.  You need to duplicate that behavior with the Pulsar Unit. Now you do not say which pulsar unit you are using, there are some where the sensor in the tank and the controller and then where the relays are all widely spaced and connect via Modbus, Profibus, hart or even 20mA loop type cabling - there may be good reasons for doing this, but if the intention is a straight swap for a flaot switch, then probably not.

However if the intention  is to  allow centralized control, then it may be better to replace a local loop of float and valve/pump or whatever with a system where the level data goes to some central point, and the instruction to turn the valve/pump or whatever comes back, allowing remote setting of the actuation level.

It rather depends why you are doing this, if you can give a bit more info, that may help.

Mike,

Hi Mike, thanks for your reply.

There's currently 4 float switches I believe. A start, an assist, a stop, and a high level.

I'm going to fit a DB6 Head in the tank, and an Ultra 4. (4 relays).

So relays 1 and 2 will need to be pump 1 on and pump 2 on. Stop level will be the same for both pumps.

Relay 3 will be a high level.

Relay 4 will be a spare/not used.

Just to note, I think the floats are wired through barrier relays which I know will no longer be required as the floats are being removed.

The reason I'm swapping the float control out for an Ultrasonic is because the floats get "stuck" and causes the pumps to run on. Generating lots of noise and dry running plus costly power consumption.

Anymore info req'd please let me know. 

Thankyou

Hi Mike, thanks for your reply.

There's currently 4 float switches I believe. A start, an assist, a stop, and a high level.

I'm going to fit a DB6 Head in the tank, and an Ultra 4. (4 relays).

So relays 1 and 2 will need to be pump 1 on and pump 2 on. Stop level will be the same for both pumps.

Relay 3 will be a high level.

Relay 4 will be a spare/not used.

Just to note, I think the floats are wired through barrier relays which I know will no longer be required as the floats are being removed.

The reason I'm swapping the float control out for an Ultrasonic is because the floats get "stuck" and causes the pumps to run on. Generating lots of noise and dry running plus costly power consumption.

Anymore info req'd please let me know. 

Thankyou

OK, so are the pumps small enough that the contacts on the Ultra 4 will be man enough, or are you going to be firing contactors to switch more power ? (and is it pumps on or off when level reached- decides the polarity of open or closing contacts.)

according to page 25 of the handbook  relay 4 is a transistor output only suited for 0.2A and 30V max. relays 1,2,3 are proper relays with change-over contacts

All four relays can be programmed for a variety of alarms, pump control, or other process functions. Three relays have contacts rated at 5A at 240V AC. The fourth is a low power solid state SPNO isolated relay, intended to be suitable for pulse counter func All connections should be fused or protected such that the short circuit capacity of the circuits to which they are connected is limited so that they do not exceed the relay rating

Given the relative cost, I'd consider a connector or an external relay if the pump rating was anywhere near that.

Mike.