Electrical works quote

[AWS 6]

Just to add on the POE/CCTV configuration:

A better way is to get a managed switch to power up all your devices, e.g. Security Gateway, Controller UI, Access Points, CCTV, Lan Ports etc. 

Use this managed switch to power up your CCTVs. Buy a NVR without POE capabilities to save cost. From the NVR User Interface, route the IP addresses from all CCTVs via the managed switch to the NVR. In this way, you can located the NVR any where in the house where there is a LAN point and need not be in the network cluster. You only need 1 Lan cable from the wall Lan port to link the NVR and you will be able to control all the CCTVs functions. Of course you will need a small monitor to view all the CCTVs real time video or view playbacks. A good start will be 4T bytes or even 8T to record 4K resolution and up to 30 days recordings. That also has to depend on the number of cameras you going to install. 

[Mandm 0]

Thanks all for your kind input!

[Snowcapper 0]

Hi, 

I got a quote for my wifi network. Does this quote look reasonable? Anyone could share on this?
 

Thanks!

[snoozee 98]

17 minutes ago, Snowcapper said:

Hi, 

I got a quote for my wifi network. Does this quote look reasonable? Anyone could share on this?
 

Thanks!

 

how big is your house that your contractor quoted you 9 access points?

HP AP22 Aruba Instant On Wi-Fi 6 AX1800 Smart Mesh Cloud Access Point - $259 online
HPE 1420 24G PoE+ (124W) Switch JH019A - $460 online
APC 500VA UPS - $120 online

one thing good about HPE products is that they have limited lifetime warranty.

if you are rebuilding your house, you should tell your electrician to pull the conduits for you first. else you will have problems trying to pull wires through walls, etc to get to the server room

Edited August 17, 2021 by snoozee

[Snowcapper 0]

26 minutes ago, snoozee said:

how big is your house that your contractor quoted you 9 access points?

HP AP22 Aruba Instant On Wi-Fi 6 AX1800 Smart Mesh Cloud Access Point - $259 online
HPE 1420 24G PoE+ (124W) Switch JH019A - $460 online
APC 500VA UPS - $120 online

one thing good about HPE products is that they have limited lifetime warranty.

if you are rebuilding your house, you should tell your electrician to pull the conduits for you first. else you will have problems trying to pull wires through walls, etc to get to the server room

Yes I’m rebuilding the house, and my builder said he can’t do the electrical work for wifi. So this company has done the electrical work. 
 

We are building a detached, 2 storey plus attic. Land 4600.

 

Honestly, the quote looks dubious to me. But my husband is just as clueless when it comes to the wifi system. Yet I’m keen to be hands on and set up the wifi after TOP with an external contractor since the wires are already pulled to a central location.

@snoozee, what do you recommend?

Edited August 17, 2021 by Snowcapper

[snoozee 98]

8 minutes ago, Snowcapper said:

Yes I’m rebuilding the house, and my builder said he can’t do the electrical work for wifi. So this company has done the electrical work. 
 

We are building a detached, 2 storey plus attic. Land 4600.

 

Honestly, the quote looks dubious to me. But my husband is just as clueless when it comes to the wifi system. Yet I’m keen to be hands on and set up the wifi after TOP with an external contractor since the wires are already pulled to a central location.

@snoozee, what do you recommend?

is the company which quoted you for WIFI is also the electrical subcon for your builder?

when i rebuilt my house, my WIFI was already planned in advanced based on the floor plans and the network wiring is part of the electrical works quote. This was done so that the electrical subcon will pull all the necessary network cables for the walls as well as ceiling (for WIFI access points) and I don't have to do add on later. It's easier to do all the conduits when construction is ongoing rather than retrofit later.

I won't say the quote is dubious but equipment markup is there and I showed you the retail pricing. the company who quoted you would have gotten the equipment even cheaper due to discounts, etc from the sales channel partners. Also there is a mistake in the quotation on the access points. The total cost is based on 10 units but quote is for 9 units only. Can't really comment on the manpower cost for configuration but if your builder's electrical subcon can pull the conduits and cables, it shouldn't cost you $2k.

To really plan out WIFI for a building, the floor plans need to be studied first so that the optimal locations for access points can be planned. Just because you have a detached house, it doesn't mean you need to have WIFI access points everywhere though this may reduce the chances of you having problems with the coverage. but too many access points may also cause you problems due to signals crossing each other and such due to the proximity of the access points. WIFI signal doesn't just cast itself in a single plane but is like a 360 degrees coverage with certain areas of the device casting more signal and certain areas casting less. for my house, i have 4 access points and when i am in my MBR in the attic, sometimes I get connected to the access point on the lower level instead of the one in my room. 

I do not know what is your house layout but if you feel this quote doesn't seem right, seek other companies to quote based on your house floor plan. then you can compare quotations and see whether this current one is fair or not.

[Kellhound 4]

As Snoozee mentioned, the floor plan needs to be studied first. In my case, I mapped out what I think are the most likely locations for fixed ethernet points and got my contractor (electrician) to lay the cables. I then have the choice to install the access points/CCTV or not later. The key thing is getting the cabling done. 

[Snowcapper 0]

Thanks Snoozee for the advice and kellhound for your inputs. Cabling is all done up for both wifi and cctv🙌🏻

I will check with another contact for second opinion. Been quite a journey building the house. Thank you
 

 

[snoozee 98]

10 hours ago, Snowcapper said:

Thanks Snoozee for the advice and kellhound for your inputs. Cabling is all done up for both wifi and cctv🙌🏻

I will check with another contact for second opinion. Been quite a journey building the house. Thank you
 

 

if your main contractor's electrician is running all the network cabling as part of your building contract, then the WIFI subcon should omit this item out from their quotation.

as mentioned before, you need to have a confirmed WIFI layout plan first before you confirm any network subcon's quotation as your electrician will need to know where to run the ceiling conduits and cable for your WIFI access points. It cannot be your electrician run the conduits and cables to where he wants and the locations are not where the WIFI access points are supposed to be at.

yes it is a tiring journey rebuilding the house but it will be a fulfilling journey when you get to the end of the line eventually.

[AWS 6]

Another topic to put up here for discussion is lightning protection. As everyone knows that climate change is definitely here and affecting the globe. More wet weather means highly more thunderstorm and lightning activities.

Most landed houses does not have a surge protection system installed other than the lightning protection system as mandated by BCA.

So, it’s worth to spend an extra amount of money to install a surge protection system by your electrical sub-con on your home electrical system to protect your household equipments.

Just sharing here some basic equipment requirements and not get ‘cheated’ by some sub-cons lack of electrical knowledge in this field.

1. Main incoming gate post meter compartment will need a type 1 arrestor to arrest the 10/350 microsecond induced wave. Minimum with 12.5kA I-impulse blocking. Total 3+1 poles(3 phase) of 50kA. Best is 25kA with total 100kA but cost of arrestor will be much higher. Choose either MOV type or Spark Gap type design. I personally prefer MOV due to technical details too lengthy to describe here.

2. Main DB inside house will need a type 2 arrestor. This is a 8/20 microsecond wave. A good spec will be same as type 1 of 25kA/100kA. But this can be reduced to half if your DB box is too tight spaced. 12.5kA/50kA will be fine too. Only MOV type for type 2.

3. Type 3 will be more demanding in terms of installation. It must be installed as near as possible to the equipments that need protection. Like network cluster, CCTVs, TVs and things of high value and importance. It’s define by Uoc. A value of 6kA is a norm.

As a reminder of the LPS (Lightning Protection System) under the new BCA regulation from 2018, only copper tape(down conductor) can be used and no longer aluminium. This is because aluminium is rather weak and easily weaken by corrosion due cement and if buried inside concrete, and once a lightning current conducts, it will break and you will have a broken link. So it’s good idea to do spot checks during structural phase to make sure only copper is used and tied to the column re-bars before casting. Once cast, you cannot see anymore and there is nothing the owner can do. This is to ensure the sub-con don’t cheat and ‘makan’ your money. 1 roll of aluminium is $140. 1 roll of copper of 1/4 the length is $380. Go work out the sums of how much they can cheat.

That’s all for now.

 

[Jack L 0]

On 9/30/2021 at 10:18 AM, AWS said:

Another topic to put up here for discussion is lightning protection. As everyone knows that climate change is definitely here and affecting the globe. More wet weather means highly more thunderstorm and lightning activities.

Most landed houses does not have a surge protection system installed other than the lightning protection system as mandated by BCA.

So, it’s worth to spend an extra amount of money to install a surge protection system by your electrical sub-con on your home electrical system to protect your household equipments.

Thanks for the sharing, @AWS. For the surge protection devices, should one buy them and pass to the electrician for installation or request the electrician to source and install? Try to understand the common practice here 😅

 

[AWS 6]

56 minutes ago, Jack L said:

Thanks for the sharing, @AWS. For the surge protection devices, should one buy them and pass to the electrician for installation or request the electrician to source and install? Try to understand the common practice here 😅

 

I guess if you already have signed your building contract with the main con, there will be a M&E sub-con works included. You can check in your electrical scope of works if surge protector system is included. If not, you can always request for installation and the main con will put this item under Variation Order. Check with main con or sub con how much they are charging first before committing. With the charge amount in mind, then work out your sums to determine if it’s cheaper to let the electrical con carry out the installation or you can after top, engage an outside LEW to install. 
Type 1 protector market price $500 and above depending on specs and brand.

Type 2 Hager(Germany) brand SPM440E $200/$250(cheapest in market) compared to brands like ABB(France)or DEHN(Germany)or FURSE(UK). Beware of Schneider due risk of MIC imitation.

Type 3 Furse brand ESP240-5A $150-$200

But in the market there is Type 1+Type 2 by Hager or Dehn. This is 2 in 1 protector in one housing. Around $1000. 

Furse has a Type 1+Type 2 +Type 3. But this Type 3 function will not be effective as this protector is installed in the meter compartment because Type 3 need to be installed as close as possible to the household equipment to be protected.

 

[Jack L 0]

On 10/2/2021 at 10:54 AM, AWS said:

I guess if you already have signed your building contract with the main con, there will be a M&E sub-con works included. You can check in your electrical scope of works if surge protector system is included. If not, you can always request for installation and the main con will put this item under Variation Order. Check with main con or sub con how much they are charging first before committing. With the charge amount in mind, then work out your sums to determine if it’s cheaper to let the electrical con carry out the installation or you can after top, engage an outside LEW to install. 

Thanks, @AWS, very detailed information. I'll buy all 3 types of SPD by myself in that case

BTW, it seems to me that most of the electricity safety measures rely on the grounding - so proper grounding is super important. 

[AWS 6]

10 hours ago, Jack L said:

Thanks, @AWS, very detailed information. I'll buy all 3 types of SPD by myself in that case

BTW, it seems to me that most of the electricity safety measures rely on the grounding - so proper grounding is super important. 

Yes, surge current & lightning current needs to be discharged into the ground(soil). Singapore earthing system is TT standard. UK is slightly different as they use TN-S. TT means the earthing is via ground electrode rod. Just like our lightning protection system (LPS) too. Make sure the electrical sub-con use a good quality earth rod/electrode. Must be solid copper or stainless steel and not any steel bar due long term issues of corrosion and end up loosing your earth electrode leading to high ohm resistance of greater than 1.

Talk to your electrical sub con and they should have knowledge. If not, then start to be wary as there are quite an amount of half past six certified LEW who has not much knowledge on Lightning Protection System(LPS) and Surge Protection System/Device (SPS/SPD).

Edited October 3, 2021 by AWS

[Itanium 1]

On 4/17/2021 at 6:53 PM, snoozee said:

Wall mounted AP is more for when there are existing LAN points on the wall but no LAN points in the ceiling. Performance wise, ceiling mounted would be better than wall mounted due to how the signals are cast. 
since you are renovating your house just pull points for ceiling and use ceiling mounted AP.

Hi Bro Snoozee

May I ask how may ceiling mounted AP do you have per floor? Are the signals strong enough to penetrate the bedrooms on the same floor and their attached bathrooms?

Thanks!