{"id":294,"date":"2022-10-06T01:16:39","date_gmt":"2022-10-06T01:16:39","guid":{"rendered":"https:\/\/gerardweatherby.org\/camping\/?p=294"},"modified":"2023-02-17T11:09:47","modified_gmt":"2023-02-17T11:09:47","slug":"casita-electricity","status":"publish","type":"post","link":"https:\/\/gerardweatherby.org\/camping\/casita-electricity\/","title":{"rendered":"Casita electricity"},"content":{"rendered":"\n
\n

Do you swear to tell the truth, the whole truth, and nothing but the Truth?<\/p>\n13th century England<\/a><\/cite><\/blockquote>\n\n\n\n

I’m not going to tell you the whole truth.<\/p>\n\n\n\n

\n

All models are wrong, but some models are useful.<\/p>\nGeorge Box<\/a><\/cite><\/blockquote>\n\n\n\n

I’m going to tell you the basics and omit some details. When folks discuss electricity, it’s common for them to use verbal shortcuts, which can lead to confusion if you’re new to the subject.
<\/p>\n\n\n\n

Basics: Volts times amps is power<\/h2>\n\n\n\n

The energy available to push an electron is voltage, measured in Volts1<\/sub>. How many electrons are flowing is current, measured in Amperes (Amps). The Volts times the Amps is power, measured in Watts.<\/p>\n\n\n\n

The main bus<\/h2>\n\n\n\n

The primary electric system in your Casita is called 12 Volts, Direct Current, or 12V or 12VDC. Or the DC bus. All the same thing.<\/p>\n\n\n\n

It’s simplest to say it powers everything except:
The Air Conditioning unit (including the heat strip).
The regular house-style outlets in your trailer.
The refrigerator, sometimes.

12 Volts is good for vehicle systems because the voltage is low enough that it’s highly unlikely to cause electrocution if there is an electrical fault.<\/p>\n\n\n\n

Alternating Current (AC) bus<\/h2>\n\n\n\n

If your trailer is plugged in, it’s receiving what’s called 120 Volts, Alternating Current. Or 110 or 120V, or the AC power. All the same thing. It powers:
The Air Conditioning unit.
The house-style outlets.
The refrigerator, probably.
The converter<\/strong><\/em>, which uses 120 AC to power the main 12 VDC bus.

120AC is good because it requires less current to deliver power, but it definitely can kill someone. The 120 AC runs in your trailer are short, insulated, and enclosed.<\/p>\n\n\n\n

DC power sources<\/h2>\n\n\n\n

The main bus is powered by a battery when there is nothing else to power it. The battery has to be recharged periodically. It can be charged by:
The converter, if the trailer is plugged in using the shore power cable on the driver’s side.
The tow vehicle, if plugged in using the connector by the hitch.
Solar panels if you have them.

Even with things turned off, there are things like a propane detector still energized, so there is often a battery disconnect<\/strong> to isolate the battery so it doesn’t drain as fast while you store the trailer. (Even if disconnected, the battery will slowly drain over time.)

Your brakes are electric. They’re normally powered by the 7-pin connector from your tow vehicle. The red breakaway cable locks the brakes if the Casita gets disconnected while towing. The power for this comes from the battery, so don’t disconnect the battery while towing.<\/strong><\/p>\n\n\n\n

Voltage: the fine print<\/h2>\n\n\n\n

12V (DC) and 120V (AC) are nominal<\/em> voltages — what we call the circuits to help keep them straight. The voltage is not exactly those numbers.

What’s called 120 (or 110) is the US household standard. It has varied over the years and localities, but today it’s probably within a volt or two of 120.

DC voltage depends on whether something is charging the battery and, if it’s not being charged, how much charge it has left and how fast it’s being discharged. <\/p>\n\n\n\n

To and fro<\/h2>\n\n\n\n

A converter<\/em> comes with your trailer and converts AC to DC. Some owners have a gizmo to convert DC to AC, but that’s called an inverter<\/em>.<\/p>\n\n\n\n

Footnotes<\/h6>\n\n\n\n

1<\/sub> Yeah, not really true. Voltage is energy per Coulomb, and it’s charge, not electrons, that really matter, and other particles, such as muons,<\/a> have charge … see All models are wrong<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Do you swear to tell the truth, the whole truth, and nothing but the Truth? 13th century England I’m not going to tell you the whole truth. All models are wrong, but some models are useful. George Box I’m going to tell you the basics and omit some details. When folks discuss electricity, it’s common […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"no-sidebar","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[8],"tags":[],"class_list":["post-294","post","type-post","status-publish","format-standard","hentry","category-electrical"],"jetpack_featured_media_url":"","jetpack-related-posts":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/posts\/294","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/comments?post=294"}],"version-history":[{"count":5,"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/posts\/294\/revisions"}],"predecessor-version":[{"id":393,"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/posts\/294\/revisions\/393"}],"wp:attachment":[{"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/media?parent=294"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/categories?post=294"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gerardweatherby.org\/camping\/wp-json\/wp\/v2\/tags?post=294"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}