Anyone much experience with Relays?

IrishSparks · Jul 20, 2010

I'm embarrassed to say I know very little about Relays.
Never really had much dealings with them.
I have a job next week and from the email I got from the company I will have to do the following:

1: Install new speed drives in new enclosure with MCBs ( Either 1 or 2 Drives )

2: Mount new Panel on AHU

3: Either pull back Motor cables or install new cable if necessary from motors into new panel ( either1 or 2 motors depending on Unit ) max run approx 10m

4: Run new mains cable from existing panel to power drive panel ( Max run approx. 10m)

5: Connect mains and motor cables

6: Remove existing contactors and install relays for new control.

7: Relays powered by existing contactor supplies.

8: Aux controls through contactors now across new relays.

9: Enable and fault control via .75 multicore cable run from new relays to drives.

10: Test and commission drives and AHU unit operation

The bits in Bold are the ones I am having issue's with,I have never done this so am a bit worried how it will work out.
This is a big contract for me as there will be 45 of these jobs to be done,all exactly the same in different buildings across Ireland,so I want to be sure I have it right from the start.
Any advice would be great.

pmac10 · Jul 20, 2010

IrishSparks said:
I'm embarrassed to say I know very little about Relays.
Never really had much dealings with them.
I have a job next week and from the email I got from the company I will have to do the following:

1: Install new speed drives in new enclosure with MCBs ( Either 1 or 2 Drives )

2: Mount new Panel on AHU

3: Either pull back Motor cables or install new cable if necessary from motors into new panel ( either1 or 2 motors depending on Unit ) max run approx 10m

4: Run new mains cable from existing panel to power drive panel ( Max run approx. 10m)

5: Connect mains and motor cables

6: Remove existing contactors and install relays for new control.

7: Relays powered by existing contactor supplies.

8: Aux controls through contactors now across new relays.

9: Enable and fault control via .75 multicore cable run from new relays to drives.

10: Test and commission drives and AHU unit operation

The bits in Bold are the ones I am having issue's with,I have never done this so am a bit worried how it will work out.
This is a big contract for me as there will be 45 of these jobs to be done,all exactly the same in different buildings across Ireland,so I want to be sure I have it right from the start.
Any advice would be great.

remove the contactors but identify and retain the wires connected to A1/A2. the contactors will have Auv contacts, these will be labelled Normally Open or Normally Closed, identify and retain these in their respective pairs. depending on the drive it may have an onboard powersupply (24VDC). take this supply to a N/O contact(likly) on the relay and from here back to the drive enable/run terminal. most drives have a fault internal relay. you may want to routue your A1 wire through that so if the drive develops a fault it will drop out your main relay.
this is a general description as i dont know drive manufacturer etc
hope this helps
perhaps this is stating the obvious but your contactor A1/A2 connects to your relay A1/A2 and match your AuX contacts to N/o or N/C on your relay

silva.foxx · Jul 20, 2010

6: Remove existing contactors and install relays for new control. The contactors previously was the DOL starter, I'm assuming, so what used to switch in the DOL will now signal to the inverter(s) in the form of a relay. The contactor is basically a robust switching relay. Again this will become the inverter run relay.

7: Relays powered by existing contactor supplies. As stated above, the relay will be signalled in the same way as the contactor.

8: Aux controls through contactors now across new relays. The relay contacts will now take the place of the contactor contacts as in switching normally open / closed as required.

9: Enable and fault control via .75 multicore cable run from new relays to drives. So using 0.75mm2 cable the relay will switch a normally open contact to signal the inverter(s) to run by utilising the inverter's onboard control PCB ie. P24 to RUN of Mitsubishi inverters and PLC and PLC to FWD of IMO Jaguar inverters.

Inverters have a fault alarm contact within there control PCB, some can be configured within the inverter parameters to switch on fault, switch when inverter ready, etc... so you may have to configure this to your needs.

Should the DOL have had an overload fitted, the wires from terms 95 & 96 can be taken through the inverter alarm contact. Also, you are best to have an auxiliary contact fitted to the mcb indicating its status, plus have a local isolator fitted close to the motor if the control panel is out of view, fitted with an auxiliary contact (pref early make/break) so the inverter does not run when the isol is off.

Finally confirm that the emergency stop and safety circuit is correct for the type of system... and all regs, etc... satisfied.

Good luck.
If you want any circuit dwgs to clarify, please let me know.

.

silva.foxx · Jul 20, 2010

Please find example attached

pmac10 · Jul 20, 2010

silva.foxx said:
Please find example attached

what software did you use to draw that mate if you dont mind me asking???

silva.foxx · Jul 21, 2010

MS Word.

I've removed some info and logos from the title bar at the bottom.

Takes a little practice and some experimenting but looks professional without the cost of CAD.
I'm certified in AutoCAD but find Word is always to hand, accessible and easy to use.

I then transfer it to .pdf so it's not too easy to copy and use in Word as a template. I'm sure it can in the right hands with shareware off the t'interweb.

Regards
s.f

pmac10 · Jul 21, 2010

silva.foxx said:
MS Word.

I've removed some info and logos from the title bar at the bottom.

Takes a little practice and some experimenting but looks professional without the cost of CAD.
I'm certified in AutoCAD but find Word is always to hand, accessible and easy to use.

I then transfer it to .pdf so it's not too easy to copy and use in Word as a template. I'm sure it can in the right hands with shareware off the t'interweb.

Regards
s.f

i,m impressed, not used autocad since 2005 so wouldnt no where to start, rececntly looked at the main screen for autocad electrical 2009 and just felt sick.
been trying to get to grips with microsoft visio but find it frustrating having to fragment/make/save your own symbols,
think ill give word a go as i use it most anyway
cheers

eco-tech · Jul 22, 2010

Can I have a beer please silver bar man ! pack man

Hmmmm... I work in ahu controls and each one is so not the same. I find removing the links, belling them out and start again is the best bet, as with a rewire of a control panel can start a lot of problems.

What is the control set up ?
What software ?
How do you propose to commission the ahu ?
Heater batts need the fan to run on after they stop or you can get a fire. Is timeclocks in the panel ?
DPS set up ?
Outside air ?
Inverters ?

Lots to think about, as you cant just change contactors for relays with a rewire.