HWH hydraulic relay

dougrainer wrote:
https://www.hwhcorp.com/ml48380.pdf

Well to put in in perspective. I have 38 years and still working on Tiffins. I have over 32 years working on HWH and have factory training at both. The system has 2 solenoids. The first solenoid just activates the system. NO real draw. It should NOT get hot just from travel. I assume the OP is stating that when he is operating the slides and/or the jacks that is when he finds that solenoid hot. IF so, then the solenoid needs replaced. I have not checked and never had too, but the system "may" de-energize when the Parking brake is released, as the jacks and slide rooms will not function on a Tiffin (or other motorhome)when the parking brake is NOT engaged. So, that would stop any concerns about the having that solenoid on. BUT, on some systems(300 series) the solenoid does stay energized when the brake is released to allow the system to go into hibernation for auto retract from road heat. HWH has built hundreds of thousands of these systems and I doubt it is a BAD ENGINEERING design. Tiffin just installs the system. The parameters are HWH parameters, NOT TIFFIN. Doug

One solenoid, i assume is the continuous duty will get hot as long as the key is on, upon ending a days drive and before using jacks or slides, the temp on the one solenoid id 215d. too hot to touch. seems to always have power to it. After operating jacks and slides, temp did not change. Solenoid only cools when key is off. Slide has been acting up. Press retract slide starts for about 2 seconds stops. Wait about 8-10 min. slide retracts normally good speed. Slide is lubed, balanced and goes in and out evenly.

1. don't know why it stops and seems to have to reset before the slide operates again - does only on retraction.
2. don't know why one solenoid is too hot to touch as long as key is on.

If you can give any thought it would be appreciated.

thanks/

There is a reason it gets hot.
It could be current flow through the main contacts or higher resistance on the coil. Continuous duty coils should not get the housing hot.

in another thread, poster having trouble with jacks signaling down while driving, but they are retracted

it was noted that there is a retract feature that checks fluid level and auto retracts when level is low, meaning a jack not fully retracted

just maybe the powered on relay/solenoid is there so the system is 'alert' and ready to respond

and like Doug says, if it gets physically hot just being energized, then it needs to be replaced

https://www.hwhcorp.com/ml48380.pdf

Well to put in in perspective. I have 38 years and still working on Tiffins. I have over 32 years working on HWH and have factory training at both. The system has 2 solenoids. The first solenoid just activates the system. NO real draw. It should NOT get hot just from travel. I assume the OP is stating that when he is operating the slides and/or the jacks that is when he finds that solenoid hot. IF so, then the solenoid needs replaced. I have not checked and never had too, but the system "may" de-energize when the Parking brake is released, as the jacks and slide rooms will not function on a Tiffin (or other motorhome)when the parking brake is NOT engaged. So, that would stop any concerns about the having that solenoid on. BUT, on some systems(300 series) the solenoid does stay energized when the brake is released to allow the system to go into hibernation for auto retract from road heat. HWH has built hundreds of thousands of these systems and I doubt it is a BAD ENGINEERING design. Tiffin just installs the system. The parameters are HWH parameters, NOT TIFFIN. Doug

On my HWH system there is an on/off switch (button) on the control. Once ignition is shut off you must push the on button to do anything further.
I did not find the 750 model on their website.

enblethen wrote:
I would be thinking about adding a manual switch in the control circuit.
A lit rocker switch of about 15 amp rating.

That's where I am headed, need to talk to HWH factory to see if there is any downside. I think it should have a way to cut power. Don't see why it is hot all the time I am driving. I think a lot of coaches have an on/off for the slide then the slide operation switch.

Still wondering why the slide outs stop and then restart after short rest.

I would be thinking about adding a manual switch in the control circuit.
A lit rocker switch of about 15 amp rating.

enblethen wrote:
It seems to be odd that the main relay is energized all the time the ignition switch is in the "on" position.

I think so, Tiffin said that's how they were, but I'm not sure that is right. HWH is still a week out on a return phone call to find out. will post when I get an answer.

That is not sound engineering.

enblethen wrote:
It seems to be odd that the main relay is energized all the time the ignition switch is in the "on" position.

I explained the reason. There is NO real current draw when it is energized. Doug