50 amp Automatic Transfer Switch with DC coils

[ALLOY]

We have a Progressive Dynamics  PD52V that hums (not the contacts) that I want to replace with a ATS that has DC coils.

Progressive Dynamics makes the PD52DCS with DC coils but it also has surge protection which is already taken care of by the EMS-HW50C

http://www.progressivedyn.com/pd52DCS.html

Parallax Power makes a ATS503 with DC coils.

http://www.parallaxpower.com/transfer-switch-50a-120-240v-ats503

 

Does anyone know of other 50amp ATS that have DC coils?

 

 

 

 

[57becky]

The only problem with this is, say your batteries are low, and you need 120 volts from either a pedestal or a generator to get your charger/converter to charge the batteries, how do you get enough DC voltage to close the contactor in the transfer switch?

[morninghill]

Esco lpt50brd if you want 50amp model. Dc coils. I've installed 2, no hum, no problems. All cables enter one side, be sure dimensions and orientation fit your space.

 

rvpowerhouse has good prices on these.

[smith4]

57becky has a point about it being preferable to use 120 VAC line power to control the coil. There are a few other options if you want to use AC line power but use DC coils for better contact life and reduced humming. One option is to install a full wave bridge rectifier on the AC power going to the coil, then use a 125 VDC coil. Another option, if you want to scrounge parts from medium voltage motor controllers, is to use a contactor economizing module. The CEM takes in 120 VAC power going to control the coil. Initially when it receives power it passes rectified 120 VAC to the coil, then after a few seconds it drops the voltage down to maybe 20-30 VDC, I don't recall exactly. This prolongs the coil life and eliminates the humming.

[Zulu]

On 8/6/2017 at 10:30 AM, morninghill said:

Esco lpt50brd if you want 50amp model. Dc coils. I've installed 2, no hum, no problems. All cables enter one side, be sure dimensions and orientation fit your space.

x2. Here's one source: RV Upgrades.