In one of my previous projects we had three transformers working in parallel.This required a synchrocheck relay to check the magnitude of Voltage, phase angle and frequency. However , is it possible to run a generator and Distribution transformer permanently(The generator is not used as a...
Hi all,
I have a simple but important question.
Can we use Brass Glands for Aluminum Wire Armoured SIngle Core Cables ?? The gland plate material is Aluminium.
Hi..
1. Is it recommended to use 4 Core Cables for '3 phase applications without neutral'? Then the neutral will have to be left unterminated at either ends right..? Also would it lead to any induced currents in the neutral Core..?
You might have heard of LV Panels with Forms of separation Form 2 and Form 4.Our Consultant has proposed a hybrid variant..with Form 4 Incoming section(2 incomers+1 buscoupler) and form 2 for outgoings(Hvac Loads)... Is this a common arrangement??I presume the only benefit will be cost savings..?
I would like to know weather fuses used in motor starters are time delay fuses.Please find the specific fuse type we have used in the attached Image..Are these fuses time delay fuses..?
The transformer size is 1600 KVA.With rated amps 2100 Amps...The breaker is 2500A 4P,drawout motorized acb with micrologic trip unit with O/L,S/C & E/F protection-100 KA/1sec,make:schneider elctric,Model:NW25 H2+Micrologic 6.0 A..The locked rotor starting time of pump is 10 sec as per motor data...
I have 45 KW Chilled water constant flow pump.It was earlier proposed to start it by DOL.But now due to limitation in incomer breaker size and transformer capacity we have to go for another method of starting.Which method can I use so that I can keep starting current to the least possible...
I have a Electrical Panel feeding two chillers of FLA 1003A ,two pumps of FLA 81 A,one AHU of FLA 12 A,a Lighting DB 16 A..The incoming breaker(Motorized ACB) size for this panel is 2500 A. Busbar rating 2500 A with SC rating of 100 KA for 1 sec.Can you guys pls tell me weather the incomer...
I think all of you in the electrical fraternity would agree with me when I say that a 45 KW Pump or AHU needs a suitable starter such as Star/delta or VFD to reduce starting current.
However, my company thinks different.They say and show me SLD's where they have fed 45 KW & Above...
Anybody here have any idea about working of Air cooled condensing units? They have more than one compressor..I want to know wheather all these compressors turn on simultaneously or in steps..? I wanted to know the starting current..
In an ACCU(Air cooled condensing unit) ,there are more than one condenser..Do all these compressors are turned ON when initially started..Or do they start in sequence?
Hi All,
I'm working in an HVAC contracting company.I'm preparing a load schedule to be submitted to our Consultant for one of our projects.I have to mention specifically the type of load(Continuos,standby,intermittent).As per my understanding AHU & ACCU are continuous loads.is it correct?.What...
Hi All,
I'm working in an HVAC contracting company.I'm preparing a load schedule to be submitted to our Consultant for one of our projects.I have to mention specifically the type of load(Continuos,standby,intermittent).As per my understanding AHU & ACCU are continuous loads.is it correct?.What...
Hi all,
Condensing Units namely Trane model no RAUJ C80..Do they have inbuilt star/delta starters..? There are six compressors and eight condensing fans in this unit.How is the sequence of operation of these? Are all compressors started at once? If not what is the time delay between turning on...
Hi all,
Could you explain what is the basic difference between ELCB and ELR+CBCT schemes ? I know that both are used in outgoing feeders for Earth leakage protection..But how different is their application..
My idea is that ELCB is used for small rating outgoing feeders and for higher...
Dear All,
I've been terribly confused over sizing cables for a 530 KW LV CHILLER.My current sizing is to go with 3 Run SIngle core 400 sq.mm cables per phase(total of 9).My cable arrangement for direct buried cables will be as attached.Can I take group derating factor to be 1 since trefoil...
I have a LV chiller of 530 KW(LoAD Amps-1049 A)..I did the cable sizing and am planning to use Single core 400 sq.mm cables(3 Runs per Phase) for this chiller .I used a derating factor of 0.699.Guys, do think Single core 400 would suffice for this chiller..?(From experience..)?
Dear Sirs,
I am working in an HVAC contracting company.We use feild disconnectors at site near equipments like AHU'S,package units etc..Could anyone enlighten how to size disconnector for such applications? Please note that the purpose of disconnector is for isolation and maintanence and does...
I have 4 runs of single core 630 mm2 cable running between AMF panel and Feeder pillar..The feeder pillar side cable is not terminated while it is already terminated in the AMF Panel.I want to meggar these cables.Should I open the termination at AMF panel side before meggaring?
Or si it good if...
Hi All,
I'm using field isolators to connect HVAC equipments such as AHU'S,package units etc to the Electrical Panel.The main purpose of providing the field isolator is only for isolation and maintanence of equipment.How should i size the Isolators for the equipment?Usully I give a 10% margin...
