I had an almost identical setup on my Rostock.
Yes, it will power it, but not for long. Many rated specs for parts are actually a bit off and this goes double for cheap Chinese power supplies.
Bed, expect anywhere from 10-12amps
Motors, while they don't all pull max amps all the time, they can pull a full amp each, so 4-5 amps depending on the number of steppers.
Hot end, can pull 3.3 to 5 amps, like motors, this isn't a constant.
There is also some misc. power lost due to electronics and cooling fans (figure 1/3rd amp each).
It gets worse, your power supply, while rated at 20, may actually only be good for 16 under normal conditions.; The Chinese are either extremely optimistic or they use some unknown measurement known only to them, either way, it never does what they claim. Also remember, power supplies do not like running at full power. Bottom line, don't expect your cheap power supply to last more than a few months, I think mine lasted 3.
What I actually found I like best when I was using Ramps, was using a small 6 amp power brick for the electronics, and a separate 10amp brick for the bed. The bed power brick died after 8 months, but it was convenient in that I could leave it at home and still print PLA. They are also cheap and if one power supply failed, I could use the other and still print PLA. No down time. In your case, if you never transport your printer, buy a cheap power brick for the electronics and just use the 20amp for your bed. If you just want a single power supply, look into a 30 amp or convert a PC power supply that has 30 amps on the 12v line (important!).
Yes, it will power it, but not for long. Many rated specs for parts are actually a bit off and this goes double for cheap Chinese power supplies.
Bed, expect anywhere from 10-12amps
Motors, while they don't all pull max amps all the time, they can pull a full amp each, so 4-5 amps depending on the number of steppers.
Hot end, can pull 3.3 to 5 amps, like motors, this isn't a constant.
There is also some misc. power lost due to electronics and cooling fans (figure 1/3rd amp each).
It gets worse, your power supply, while rated at 20, may actually only be good for 16 under normal conditions.; The Chinese are either extremely optimistic or they use some unknown measurement known only to them, either way, it never does what they claim. Also remember, power supplies do not like running at full power. Bottom line, don't expect your cheap power supply to last more than a few months, I think mine lasted 3.
What I actually found I like best when I was using Ramps, was using a small 6 amp power brick for the electronics, and a separate 10amp brick for the bed. The bed power brick died after 8 months, but it was convenient in that I could leave it at home and still print PLA. They are also cheap and if one power supply failed, I could use the other and still print PLA. No down time. In your case, if you never transport your printer, buy a cheap power brick for the electronics and just use the 20amp for your bed. If you just want a single power supply, look into a 30 amp or convert a PC power supply that has 30 amps on the 12v line (important!).