Does 250W MH need to be plugged into mains?

[ervine]

Hi guys,

I FINALLY FINALLY got my 250W bulb!! I fired up my modded victron casing and it's working fine.. already did up a DIY PVC rack to hold the casing, that is working too...

Now all I need to know is if I need to plug the 250W MH directly to the mains, can I just plug it in along with an existing extension cord that is currently used to power my pumps?

Also, can "The Ben" timer tahan the MH?

Thanks!

Ervine

[Achilles Tang]

Just make sure your extension cord does not have too many high amperage equipment on it. Or it could overload/catch fire!

The Ben timers cannot tolerate high amps. Using it for my 400w lamps usually means it won't turn on or turn off... the contacter inside will 'stick'.

I'm no electrical guru... maybe someone else can give a more technical answer!

[BarraCudaTM]

I'm currently using 2x250 on a single theben timer so far so good. Some timers when used for a high inductive load will cause the metal contacts to melt and weld together.

[ervine]

Hm... is one 2500l/h pump (50W?) + one 2800l/h pump (100W) + one table fan (?W) + one 250W MH considered overloaded?

Die.. I also realised that this particular extension cord is also connected to mains via a multiplug!!!!

[CalciumReef]

im running my 1.25 hp chiller,400w mh and some pumps on one gang socket

[DaY]

Pls ensure that your extension cord is able to withstand all those ampere. Usually for those large wattage application, it is advisable to plug them directly into the main switch without going through all those extension cords etc. There has been alot of cases whereby application overload the switches and catch fire. (most recent is the East Coast Rd case, whereby someone die if you read the newspaper)

[ervine]

haha okay so that means quite safe... phew... better do it over the weekend when I can monitor it carefully... thanks for the help!

[CalciumReef]

Yup.My extension switches are "diy" one.I used thick wires.So no worries for me

[nutx]

haha okay so that means quite safe... phew... better do it over the weekend when I can monitor it carefully... thanks for the help!

I think there are a few factors to consider:

1. Is the wall plug a single unit to the main, or share among the other wall plugs. (roidan's 6ft tank thread, did mentioned something on this).

The total loading (or shared among all the common wall plugs) is something like 3000watts. (need to be confirmed)

2. For extension cord, the more branded(=expensive) will usually state the loading they can take.

so you will have to calculate/judge yourself whether the quality of the extension cord can handle the loading.

[ervine]

Aiyah die.. mine is a super cheapo extension cord... Hmmmm.....

Oh and it's a shared plug...

[RockyBoy]

Hm... is one 2500l/h pump (50W?) + one 2800l/h pump (100W) + one table fan (?W) + one 250W MH considered overloaded?

Die.. I also realised that this particular extension cord is also connected to mains via a multiplug!!!!

Quite easy to calculate the current (ampere)

pump1 - 50W

pump2 - 100W

table fan - abt 20W

MH light - 250W

Some equipment has losses such especially ballast loss (in form of heat). So add about 30% to the MH light = 325W. Pump, at 10% losses. Fan no need to add anything lar.

So total wattages plus losses = 55+110+20+325 = 510Watts

Current (ampere) = Power (Watts) / Voltage (230V)

= 510/230 = 2.2A

So your timer or extension plugs should have higher ratings than this say, minimum 5Amps. (Give additional allowance about 1.5times of your calculated current usage). Will not heat your cables also.

Take not for those having chillers because chillers have starting current of at least 7-10 times the rated chiller current. So your cables, plugs, timers should be able to take the sudden surge of current for a few seconds.

[RockyBoy]

Aiyah die.. mine is a super cheapo extension cord... Hmmmm.....

Oh and it's a shared plug...

Try to reduce the cable length for those cheapo extension ones and don't coil it. So that it won't heat up & can cause unnessary tripping.

[andysho]

i also be using a 250w mh light.. a chiller on the way soon

there are 4 main socket in my room~~~

so guess have to leave 3 for my new tank

one for chiller

one for mh light

one for pump and the ret

left one for my pc keke

hmm can go and read on safety on use of electrical by a govt board.//

http://www.hpb.gov.sg/hpb/haz/haz02003.asp

[ervine]

Quite easy to calculate the current (ampere)

pump1 - 50W

pump2 - 100W

table fan - abt 20W

MH light - 250W

Some equipment has losses such especially ballast loss (in form of heat). So add about 30% to the MH light = 325W. Pump, at 10% losses. Fan no need to add anything lar.

So total wattages plus losses = 55+110+20+325 = 510Watts

Current (ampere) = Power (Watts) / Voltage (230V)

= 510/230 = 2.2A

So your timer or extension plugs should have higher ratings than this say, minimum 5Amps. (Give additional allowance about 1.5times of your calculated current usage). Will not heat your cables also.

Take not for those having chillers because chillers have starting current of at least 7-10 times the rated chiller current. So your cables, plugs, timers should be able to take the sudden surge of current for a few seconds.

Cool thanks!! I go check it out...

[coralreef]

I'm not too sure about overload....I using 3 extension....with my TV,sound system,PC, PC speaker system, 1 X 250W, 3 pumps, T5 lighting, fans...etc....so far still not on fire...haha