In mongodb 3.0 replication, how elections happen when a secondary goes down

Situation: I have a MongoDB replication set over two computers.

• One computer is a server that holds the primary node and the arbiter. This server is a live server and is always on. It's local IP that is used in replication is 192.168.0.4.
• Second is a PC that the secondary node resides on and is on for a few hours a day. It's local IP that is used in replication is 192.168.0.5.

My expectation: I wanted the live server to be the main point of data interaction of my application, regardless of the state of the PC (whether it is reachable or not, since PC is secondary), so I wanted to make sure that server's node is always primary.

The following is the result of rs.config():

liveSet:PRIMARY> rs.config()
{
    "_id" : "liveSet",
    "version" : 2,
    "members" : [
        {
            "_id" : 0,
            "host" : "192.168.0.4:27017",
            "arbiterOnly" : false,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 10,
            "tags" : {

            },
            "slaveDelay" : 0,
            "votes" : 1
        },
        {
            "_id" : 1,
            "host" : "192.168.0.5:5051",
            "arbiterOnly" : false,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {

            },
            "slaveDelay" : 0,
            "votes" : 1
        },
        {
            "_id" : 2,
            "host" : "192.168.0.4:5052",
            "arbiterOnly" : true,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {

            },
            "slaveDelay" : 0,
            "votes" : 1
        }
    ],
    "settings" : {
        "chainingAllowed" : true,
        "heartbeatTimeoutSecs" : 10,
        "getLastErrorModes" : {

        },
        "getLastErrorDefaults" : {
            "w" : 1,
            "wtimeout" : 0
        }
    }
}

Also I have set the storage engine to be WiredTiger, if that matters.

What I actually get, and the problem: When I turn off the PC, or kill its mongod process, then the node on the server becomes secondary.

The following is the output of the server when I killed PC's mongod process, while connected to primary node's shell:

liveSet:PRIMARY>
2015-11-29T10:46:29.471+0430 I NETWORK  Socket recv() errno:10053 An established connection was aborted by the software in your host machine. 127.0.0.1:27017
2015-11-29T10:46:29.473+0430 I NETWORK  SocketException: remote: 127.0.0.1:27017 error: 9001 socket exception [RECV_ERROR] server [127.0.0.1:27017]
2015-11-29T10:46:29.475+0430 I NETWORK  DBClientCursor::init call() failed
2015-11-29T10:46:29.479+0430 I NETWORK  trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed
2015-11-29T10:46:29.481+0430 I NETWORK  reconnect 127.0.0.1:27017 (127.0.0.1) ok
liveSet:SECONDARY>

1. Considering this part of MongoDB documentation:

Replica sets use elections to determine which set member will become primary. Elections occur after initiating a replica set, and also any time the primary becomes unavailable.

The election occurs when the primary is not available (or at the time of initiating, however this is part does not concern our case), but primary was always available, so why the election happens.

2. Considering this part of the same documentation:

If a majority of the replica set is inaccessible or unavailable, the replica set cannot accept writes and all remaining members become read-only.

Considering the part 'members become read-only', I have two nodes up vs one down, so this should not also affect our replication.

Now my question: How to keep the node on the server as primary, when the node on PC is not reachable?