Which power strip to take?

[cpufrost]

the issue is the surge protector is dangerous on ships. has nothing directly to do with powerstrips. this shouldnt be brought on the ship.

 

This assumption is 100% incorrect.

 

Can you tell me why a surge protector on a power strip is any different from a surge protector on a "charging device"?

 

The surge protection on the charging device is definitely not the same as a consumer power strip. First of all the power strip is a three wire device. It has a ground lug. The charger I linked to does not. The protection they advertise is completely unrelated to clamping devices between L1 and chassis ground.

 

All switch mode charging devices have to have protection to keep the high voltages inside from frying your device (and you!). Also if a neighboring device misbehaves and causes overvoltages and sags the other devices plugged in need protection. This is entirely unrelated to power input anomalies present on the primary (input at 87~250VAC 50-60Hz)

 

Electrically, these multi tap USB chargers present nothing different (hazard-wise) than a standard laptop or cell phone charger. Their main switch mode power supply is just larger to accommodate multiple, simultaneous charging.

 

Even so, this charger is still smaller than a typical high end enthusiast laptop or mobile workstation with an i7 quad core CPU and dedicated GPU, etc.

 

If they want to ban these types of chargers then they might as well ban all laptop chargers!

 

Some laptop chargers, like the Dell XPS 15 9550 I'm typing this out on now, for example, have a three prong power cord. I don't have the schematic of this particular product in front of me to be sure, but it could have a MOV since it's indeed grounded. A lot of them do. This would put this device in the same category as a consumer strip with a MOV, a consumable device which degrades in proportion to how "dirty" the power is*.

 

And yes, there would be thousands of these passing through on ships worldwide.

 

________________________________________________

 

*dirty referring to power spikes and surges, not hash and harmonic distortion.

Edited May 1, 2016 by cpufrost

[chengkp75]

This assumption is 100% incorrect.

 

 

 

The surge protection on the charging device is definitely not the same as a consumer power strip. First of all the power strip is a three wire device. It has a ground lug. The charger I linked to does not. The protection they advertise is completely unrelated to clamping devices between L1 and chassis ground.

 

All switch mode charging devices have to have protection to keep the high voltages inside from frying your device (and you!). Also if a neighboring device misbehaves and causes overvoltages and sags the other devices plugged in need protection. This is entirely unrelated to power input anomalies present on the primary (input at 87~250VAC 50-60Hz)

 

Electrically, these multi tap USB chargers present nothing different (hazard-wise) than a standard laptop or cell phone charger. Their main switch mode power supply is just larger to accommodate multiple, simultaneous charging.

 

Even so, this charger is still smaller than a typical high end enthusiast laptop or mobile workstation with an i7 quad core CPU and dedicated GPU, etc.

 

If they want to ban these types of chargers then they might as well ban all laptop chargers!

 

Some laptop chargers, like the Dell XPS 15 9550 I'm typing this out on now, for example, have a three prong power cord. I don't have the schematic of this particular product in front of me to be sure, but it could have a MOV since it's indeed grounded. A lot of them do. This would put this device in the same category as a consumer strip with a MOV, a consumable device which degrades in proportion to how "dirty" the power is*.

 

And yes, there would be thousands of these passing through on ships worldwide.

 

________________________________________________

 

*dirty referring to power spikes and surges, not hash and harmonic distortion.

 

Just because a plug has a ground connection, does not mean it is surge protected, and neither does it mean it isn't surge protected (though that certainly is more of an indicator that it might not be), since consumer electricals are designed to have the neutral at ground potential, so a surge protector could be placed between hot and neutral (and many better surge protectors have hot/neutral, neutral/ground, and hot/ground MOV's).

 

The way that a charging device protects your devices is in two ways, using a transformer and using a switching transformer, which switches on for less time as the input voltage increases, until it stops conducting altogether at a sufficiently high voltage.

 

However, to put this to rest one way or another, I am e-mailing Anker to ask whether their products have MOV surge protection or not.

[cpufrost]

Using a surge protector with only two legs (L1+N) is hazardous.

Why? Simply because in the event of a massive surge there is no way for the excessive energy to be dumped. Dumping into the neutral which is a current carrying conductor, is extremely hazardous.

 

It can be argued that "across the line" (a phrase I don't care for in single phase systems) protection with MOV is acceptable practice downstream of the internal line fuse but that was primary practice what in the 70s? Loads are much more complex and power potentially dirty so these MOVs start to conduct and blow those fuses out annoying techs. Some jump them out! (REALLY BAD!) Just clip the MOV and be done with it. Those old (linear) PSUs can take a lot of abuse compared to sensitive CMOS stuff downstream of a noisy switcher. EPROMS of the era could survive much more bad stuff...

 

Two prong devices I've used and repaired most certainly do NOT use MOVs. Most will use a fuse or resistor (low powered devices only) that provides protection in case of catastrophic failure on the primary side.

 

Like I have said numerous times, these adapters are no more of an (electrical) hazard when used on marine electrical systems than charging your laptop or cell phone.

 

Question becomes this in the future though!

 

Will requirements become more stringent with more and more devices using Lithium Polymer (LiPO) batteries? If punctured or thermally abused, these can vent violently. In an aircraft cabin crew has been trained and has a way to contain a device only if caught smoking. If flames are being emitted its another matter altogether. Fortunately for the small, sub 10Wh packs in cell phones such an event is short lived. Large laptop packs typically use an array of 18650 cells in series parallel which are far more stable. Except the new Macbook and some other "slice" format packs which are LiPo.

 

Left to their own devices in unattended living quarters they could be quite the hazard if they act up. The HF head should handle it but the cabin and contents would be trashed. Damage similar to a malfunctioning strip assuming the branch CB does not open. Usually they do limiting the damage to the smell of torched plastic. Which in that case call it lucky.

[cpufrost]

I would be interested what Anker says about MOV on input.

I have one but it works and don't want to rip it apart to see if there's one there. ;)