question regarding ssr (solid state relay) or normal relay

[mr-hilux]

Hi all
I've been reading and can not quite find the right answer for what i need.
Here it goes
I need to switch a large amount of current say 80 amps at 240 volts.
I've been looking at ssr AC - AC 80A 480VAC for the job.
My only concern is the amount of heat that it would generate and how to get ride of it and the current drop.
Does anyone know how i can work it out?
The other option that i was think of was to use jaycar relay CAT. NO. SY4044 which is rated at 240 volts at 30amps .
I can use three of these as i can spread the load over the relays giving me a total of 90 amps.
the only problem with this is it's life span.
I would prefer to use the ssr rather than the jaycar unit.
Thanks in advance for your help.
Ps i can not disclose what i'm doing with it except it's not illegal .

[Flux]

SSr's are triac based so you will have a drop of near 2v when conducting. They need heatsinks for larger currents.

For switching large currents relays of the standard type are not very suitable. Once you get above single relay ratings you would be Far better off looking at contactors.These are readily available as motor starting units but sometimes you can just buy the contactor part without the enclosure and the overload and protection gear.

For infrequent switching contactors will be better as there is virtually no loss when closed. They are not very suitable if the switching is frequent and in that case SSR's will last better. Contactors cycling continuously more than say once a minute will have a short contact life and you should use ssr and deal with the heat sink issue.

Flux